Blame - docs/0.8.7-incubating/aql/functions.html - incubator-asterixdb-site

blob: 5530768c05b9517afafa94897e1a83b14327e2fe [file] [log] [blame]

Ian Maxon	e2b799e	2015-11-24 18:20:03 -0800	[diff] [blame]	1	<!DOCTYPE html>
				2	<!--
				3	\| Generated by Apache Maven Doxia at 2015-11-24
				4	\| Rendered using Apache Maven Fluido Skin 1.3.0
				5	-->
				6	<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
				7	<head>
				8	<meta charset="UTF-8" />
				9	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
				10	<meta name="Date-Revision-yyyymmdd" content="20151124" />
				11	<meta http-equiv="Content-Language" content="en" />
				12	<title>AsterixDB – Asterix: Using Functions</title>
				13	<link rel="stylesheet" href="../css/apache-maven-fluido-1.3.0.min.css" />
				14	<link rel="stylesheet" href="../css/site.css" />
				15	<link rel="stylesheet" href="../css/print.css" media="print" />
				16
				17
				18	<script type="text/javascript" src="../js/apache-maven-fluido-1.3.0.min.js"></script>
				19
				20
				21
Ian Maxon	e2b799e	2015-11-24 18:20:03 -0800	[diff] [blame]	22
Ian Maxon	e2b799e	2015-11-24 18:20:03 -0800	[diff] [blame]	23
				24	</head>
				25	<body class="topBarDisabled">
				26
				27
				28
				29
				30	<div class="container-fluid">
				31	<div id="banner">
				32	<div class="pull-left">
				33	<a href="http://asterixdb.apache.org/" id="bannerLeft">
				34	<img src="../images/asterixlogo.png" alt="AsterixDB"/>
				35	</a>
				36	</div>
				37	<div class="pull-right"> </div>
				38	<div class="clear"><hr/></div>
				39	</div>
				40
				41	<div id="breadcrumbs">
				42	<ul class="breadcrumb">
				43
				44
				45	<li id="publishDate">Last Published: 2015-11-24</li>
				46
				47
				48
				49	<li id="projectVersion" class="pull-right">Version: 0.8.7-incubating</li>
				50
				51	<li class="divider pull-right">\|</li>
				52
				53	<li class="pull-right"> <a href="../index.html" title="Documentation Home">
				54	Documentation Home</a>
				55	</li>
				56
				57	</ul>
				58	</div>
				59
				60
				61	<div class="row-fluid">
				62	<div id="leftColumn" class="span3">
				63	<div class="well sidebar-nav">
				64
				65
				66	<ul class="nav nav-list">
				67	<li class="nav-header">Documentation</li>
				68
				69	<li>
				70
				71	<a href="../install.html" title="Installing and Managing AsterixDB using Managix">
				72	<i class="none"></i>
				73	Installing and Managing AsterixDB using Managix</a>
				74	</li>
				75
				76	<li>
				77
				78	<a href="../yarn.html" title="Deploying AsterixDB using YARN">
				79	<i class="none"></i>
				80	Deploying AsterixDB using YARN</a>
				81	</li>
				82
				83	<li>
				84
				85	<a href="../aql/primer.html" title="AsterixDB 101: An ADM and AQL Primer">
				86	<i class="none"></i>
				87	AsterixDB 101: An ADM and AQL Primer</a>
				88	</li>
				89
				90	<li>
				91
				92	<a href="../aql/primer-sql-like.html" title="AsterixDB 101: An ADM and AQL Primer (For SQL Fans)">
				93	<i class="none"></i>
				94	AsterixDB 101: An ADM and AQL Primer (For SQL Fans)</a>
				95	</li>
				96
				97	<li>
				98
				99	<a href="../aql/js-sdk.html" title="AsterixDB Javascript SDK">
				100	<i class="none"></i>
				101	AsterixDB Javascript SDK</a>
				102	</li>
				103
				104	<li>
				105
				106	<a href="../aql/datamodel.html" title="Asterix Data Model (ADM)">
				107	<i class="none"></i>
				108	Asterix Data Model (ADM)</a>
				109	</li>
				110
				111	<li>
				112
				113	<a href="../aql/manual.html" title="Asterix Query Language (AQL)">
				114	<i class="none"></i>
				115	Asterix Query Language (AQL)</a>
				116	</li>
				117
				118	<li class="active">
				119
				120	<a href="#"><i class="none"></i>AQL Functions</a>
				121	</li>
				122
				123	<li>
				124
				125	<a href="../aql/allens.html" title="AQL Allen's Relations Functions">
				126	<i class="none"></i>
				127	AQL Allen's Relations Functions</a>
				128	</li>
				129
				130	<li>
				131
				132	<a href="../aql/similarity.html" title="AQL Support of Similarity Queries">
				133	<i class="none"></i>
				134	AQL Support of Similarity Queries</a>
				135	</li>
				136
				137	<li>
				138
				139	<a href="../aql/externaldata.html" title="Accessing External Data">
				140	<i class="none"></i>
				141	Accessing External Data</a>
				142	</li>
				143
				144	<li>
				145
				146	<a href="../feeds/tutorial.html" title="Support for Data Ingestion in AsterixDB">
				147	<i class="none"></i>
				148	Support for Data Ingestion in AsterixDB</a>
				149	</li>
				150
				151	<li>
				152
				153	<a href="../udf.html" title="Support for User Defined Functions in AsterixDB">
				154	<i class="none"></i>
				155	Support for User Defined Functions in AsterixDB</a>
				156	</li>
				157
				158	<li>
				159
				160	<a href="../aql/filters.html" title="Filter-Based LSM Index Acceleration">
				161	<i class="none"></i>
				162	Filter-Based LSM Index Acceleration</a>
				163	</li>
				164
				165	<li>
				166
				167	<a href="../api.html" title="HTTP API to AsterixDB">
				168	<i class="none"></i>
				169	HTTP API to AsterixDB</a>
				170	</li>
				171	</ul>
				172
				173
				174
				175	<hr class="divider" />
				176
				177	<div id="poweredBy">
				178	<div class="clear"></div>
				179	<div class="clear"></div>
				180	<div class="clear"></div>
				181	<a href="https://code.google.com/p/hyracks/" title="Hyracks" class="builtBy">
				182	<img class="builtBy" alt="Hyracks" src="../images/hyrax_ts.png" />
				183	</a>
				184	</div>
				185	</div>
				186	</div>
				187
				188
				189	<div id="bodyColumn" class="span9" >
				190
				191	<!-- ! Licensed to the Apache Software Foundation (ASF) under one
				192	! or more contributor license agreements. See the NOTICE file
				193	! distributed with this work for additional information
				194	! regarding copyright ownership. The ASF licenses this file
				195	! to you under the Apache License, Version 2.0 (the
				196	! "License"); you may not use this file except in compliance
				197	! with the License. You may obtain a copy of the License at
				198	!
				199	! http://www.apache.org/licenses/LICENSE-2.0
				200	!
				201	! Unless required by applicable law or agreed to in writing,
				202	! software distributed under the License is distributed on an
				203	! "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
				204	! KIND, either express or implied. See the License for the
				205	! specific language governing permissions and limitations
				206	! under the License.
				207	! --><h1>Asterix: Using Functions</h1>
				208	<div class="section">
				209	<h2><a name="Table_of_Contents"></a><a name="toc" id="toc">Table of Contents</a></h2>
				210
				211	<ul>
				212
				213	<li><a href="#NumericFunctions">Numeric Functions</a></li>
				214
				215	<li><a href="#StringFunctions">String Functions</a></li>
				216
				217	<li><a href="#AggregateFunctions">Aggregate Functions</a></li>
				218
				219	<li><a href="#SpatialFunctions">Spatial Functions</a></li>
				220
				221	<li><a href="#SimilarityFunctions">Similarity Functions</a></li>
				222
				223	<li><a href="#TokenizingFunctions">Tokenizing Functions</a></li>
				224
				225	<li><a href="#TemporalFunctions">Temporal Functions</a></li>
				226
				227	<li><a href="#RecordFunctions">Record Functions</a></li>
				228
				229	<li><a href="#OtherFunctions">Other Functions</a></li>
				230	</ul>
				231	<p>Asterix provides various classes of functions to support operations on numeric, string, spatial, and temporal data. This document explains how to use these functions.</p></div>
				232	<div class="section">
				233	<h2><a name="Numeric_Functions_Back_to_TOC"></a><a name="NumericFunctions" id="NumericFunctions">Numeric Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				234	<div class="section">
				235	<h3><a name="abs"></a>abs</h3>
				236
				237	<ul>
				238
				239	<li>
				240	<p>Syntax:</p>
				241
				242	<div class="source">
				243	<div class="source">
				244	<pre>abs(numeric_expression)
				245	</pre></div></div></li>
				246
				247	<li>
				248	<p>Computes the absolute value of the argument.</p></li>
				249
				250	<li>Arguments:
				251
				252	<ul>
				253
				254	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt>/<tt>float</tt>/<tt>double</tt> value.</li>
				255	</ul></li>
				256
				257	<li>Return Value:
				258
				259	<ul>
				260
				261	<li>The absolute value of the argument with the same type as the input argument, or <tt>null</tt> if the argument is a <tt>null</tt> value.</li>
				262	</ul></li>
				263
				264	<li>
				265	<p>Example:</p>
				266
				267	<div class="source">
				268	<div class="source">
				269	<pre>let $v1 := abs(2013)
				270	let $v2 := abs(-4036)
				271	let $v3 := abs(0)
				272	let $v4 := abs(float("-2013.5"))
				273	let $v5 := abs(double("-2013.593823748327284"))
				274	return { "v1": $v1, "v2": $v2, "v3": $v3, "v4": $v4, "v5": $v5 }
				275	</pre></div></div></li>
				276	</ul>
				277
				278	<ul>
				279
				280	<li>
				281	<p>The expected result is:</p>
				282
				283	<div class="source">
				284	<div class="source">
				285	<pre>{ "v1": 2013, "v2": 4036, "v3": 0, "v4": 2013.5f, "v5": 2013.5938237483274d }
				286	</pre></div></div></li>
				287	</ul></div>
				288	<div class="section">
				289	<h3><a name="ceiling"></a>ceiling</h3>
				290
				291	<ul>
				292
				293	<li>
				294	<p>Syntax:</p>
				295
				296	<div class="source">
				297	<div class="source">
				298	<pre>ceiling(numeric_expression)
				299	</pre></div></div></li>
				300
				301	<li>
				302	<p>Computes the smallest (closest to negative infinity) number with no fractional part that is not less than the value of the argument. If the argument is already equal to mathematical integer, then the result is the same as the argument.</p></li>
				303
				304	<li>Arguments:
				305
				306	<ul>
				307
				308	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt>/<tt>float</tt>/<tt>double</tt> value.</li>
				309	</ul></li>
				310
				311	<li>Return Value:
				312
				313	<ul>
				314
				315	<li>The ceiling value for the given number in the same type as the input argument, or <tt>null</tt> if the input is <tt>null</tt>.</li>
				316	</ul></li>
				317
				318	<li>
				319	<p>Example:</p>
				320
				321	<div class="source">
				322	<div class="source">
				323	<pre>let $v1 := ceiling(2013)
				324	let $v2 := ceiling(-4036)
				325	let $v3 := ceiling(0.3)
				326	let $v4 := ceiling(float("-2013.2"))
				327	let $v5 := ceiling(double("-2013.893823748327284"))
				328	return { "v1": $v1, "v2": $v2, "v3": $v3, "v4": $v4, "v5": $v5 }
				329	</pre></div></div></li>
				330	</ul>
				331
				332	<ul>
				333
				334	<li>
				335	<p>The expected result is:</p>
				336
				337	<div class="source">
				338	<div class="source">
				339	<pre>{ "v1": 2013, "v2": -4036, "v3": 1.0d, "v4": -2013.0f, "v5": -2013.0d }
				340	</pre></div></div></li>
				341	</ul></div>
				342	<div class="section">
				343	<h3><a name="floor"></a>floor</h3>
				344
				345	<ul>
				346
				347	<li>
				348	<p>Syntax:</p>
				349
				350	<div class="source">
				351	<div class="source">
				352	<pre>floor(numeric_expression)
				353	</pre></div></div></li>
				354
				355	<li>
				356	<p>Computes the largest (closest to positive infinity) number with no fractional part that is not greater than the value. If the argument is already equal to mathematical integer, then the result is the same as the argument.</p></li>
				357
				358	<li>Arguments:
				359
				360	<ul>
				361
				362	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt>/<tt>float</tt>/<tt>double</tt> value.</li>
				363	</ul></li>
				364
				365	<li>Return Value:
				366
				367	<ul>
				368
				369	<li>The floor value for the given number in the same type as the input argument, or <tt>null</tt> if the input is <tt>null</tt>.</li>
				370	</ul></li>
				371
				372	<li>
				373	<p>Example:</p>
				374
				375	<div class="source">
				376	<div class="source">
				377	<pre>let $v1 := floor(2013)
				378	let $v2 := floor(-4036)
				379	let $v3 := floor(0.8)
				380	let $v4 := floor(float("-2013.2"))
				381	let $v5 := floor(double("-2013.893823748327284"))
				382	return { "v1": $v1, "v2": $v2, "v3": $v3, "v4": $v4, "v5": $v5 }
				383	</pre></div></div></li>
				384	</ul>
				385
				386	<ul>
				387
				388	<li>
				389	<p>The expected result is:</p>
				390
				391	<div class="source">
				392	<div class="source">
				393	<pre>{ "v1": 2013, "v2": -4036, "v3": 0.0d, "v4": -2014.0f, "v5": -2014.0d }
				394	</pre></div></div></li>
				395	</ul></div>
				396	<div class="section">
				397	<h3><a name="round"></a>round</h3>
				398
				399	<ul>
				400
				401	<li>
				402	<p>Syntax:</p>
				403
				404	<div class="source">
				405	<div class="source">
				406	<pre>round(numeric_expression)
				407	</pre></div></div></li>
				408
				409	<li>
				410	<p>Computes the number with no fractional part that is closest (and also closest to positive infinity) to the argument.</p></li>
				411
				412	<li>Arguments:
				413
				414	<ul>
				415
				416	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt>/<tt>float</tt>/<tt>double</tt> value.</li>
				417	</ul></li>
				418
				419	<li>Return Value:
				420
				421	<ul>
				422
				423	<li>The rounded value for the given number in the same type as the input argument, or <tt>null</tt> if the input is <tt>null</tt>.</li>
				424	</ul></li>
				425
				426	<li>
				427	<p>Example:</p>
				428
				429	<div class="source">
				430	<div class="source">
				431	<pre>let $v1 := round(2013)
				432	let $v2 := round(-4036)
				433	let $v3 := round(0.8)
				434	let $v4 := round(float("-2013.256"))
				435	let $v5 := round(double("-2013.893823748327284"))
				436	return { "v1": $v1, "v2": $v2, "v3": $v3, "v4": $v4, "v5": $v5 }
				437	</pre></div></div></li>
				438	</ul>
				439
				440	<ul>
				441
				442	<li>
				443	<p>The expected result is:</p>
				444
				445	<div class="source">
				446	<div class="source">
				447	<pre>{ "v1": 2013, "v2": -4036, "v3": 1.0d, "v4": -2013.0f, "v5": -2014.0d }
				448	</pre></div></div></li>
				449	</ul></div>
				450	<div class="section">
				451	<h3><a name="round-half-to-even"></a>round-half-to-even</h3>
				452
				453	<ul>
				454
				455	<li>
				456	<p>Syntax:</p>
				457
				458	<div class="source">
				459	<div class="source">
				460	<pre>round-half-to-even(numeric_expression, [precision])
				461	</pre></div></div></li>
				462
				463	<li>
				464	<p>Computes the closest numeric value to <tt>numeric_expression</tt> that is a multiple of ten to the power of minus <tt>precision</tt>. <tt>precision</tt> is optional and by default value <tt>0</tt> is used.</p></li>
				465
				466	<li>Arguments:
				467
				468	<ul>
				469
				470	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt>/<tt>float</tt>/<tt>double</tt> value.</li>
				471
				472	<li><tt>precision</tt>: An optional integer field representing the number of digits in the fraction of the the result</li>
				473	</ul></li>
				474
				475	<li>Return Value:
				476
				477	<ul>
				478
				479	<li>The rounded value for the given number in the same type as the input argument, or <tt>null</tt> if the input is <tt>null</tt>.</li>
				480	</ul></li>
				481
				482	<li>
				483	<p>Example:</p>
				484
				485	<div class="source">
				486	<div class="source">
				487	<pre>let $v1 := round-half-to-even(2013)
				488	let $v2 := round-half-to-even(-4036)
				489	let $v3 := round-half-to-even(0.8)
				490	let $v4 := round-half-to-even(float("-2013.256"))
				491	let $v5 := round-half-to-even(double("-2013.893823748327284"))
				492	let $v6 := round-half-to-even(double("-2013.893823748327284"), 2)
				493	let $v7 := round-half-to-even(2013, 4)
				494	let $v8 := round-half-to-even(float("-2013.256"), 5)
				495	return { "v1": $v1, "v2": $v2, "v3": $v3, "v4": $v4, "v5": $v5, "v6": $v6, "v7": $v7, "v8": $v8 }
				496	</pre></div></div></li>
				497	</ul>
				498
				499	<ul>
				500
				501	<li>
				502	<p>The expected result is:</p>
				503
				504	<div class="source">
				505	<div class="source">
				506	<pre>{ "v1": 2013, "v2": -4036, "v3": 1.0d, "v4": -2013.0f, "v5": -2014.0d, "v6": -2013.89d, "v7": 2013, "v8": -2013.256f }
				507	</pre></div></div></li>
				508	</ul></div></div>
				509	<div class="section">
				510	<h2><a name="String_Functions_Back_to_TOC"></a><a name="StringFunctions" id="StringFunctions">String Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				511	<div class="section">
				512	<h3><a name="string-to-codepoint"></a>string-to-codepoint</h3>
				513
				514	<ul>
				515
				516	<li>
				517	<p>Syntax:</p>
				518
				519	<div class="source">
				520	<div class="source">
				521	<pre>string-to-codepoint(string_expression)
				522	</pre></div></div></li>
				523
				524	<li>
				525	<p>Converts the string <tt>string_expression</tt> to its code-based representation.</p></li>
				526
				527	<li>Arguments:
				528
				529	<ul>
				530
				531	<li><tt>string_expression</tt> : A <tt>string</tt> that will be converted.</li>
				532	</ul></li>
				533
				534	<li>Return Value:
				535
				536	<ul>
				537
				538	<li>An <tt>OrderedList</tt> of the code points for the string <tt>string_expression</tt>.</li>
				539	</ul></li>
				540	</ul></div>
				541	<div class="section">
				542	<h3><a name="codepoint-to-string"></a>codepoint-to-string</h3>
				543
				544	<ul>
				545
				546	<li>
				547	<p>Syntax:</p>
				548
				549	<div class="source">
				550	<div class="source">
				551	<pre>codepoint-to-string(list_expression)
				552	</pre></div></div></li>
				553
				554	<li>
				555	<p>Converts the ordered code-based representation <tt>list_expression</tt> to the corresponding string.</p></li>
				556
				557	<li>Arguments:
				558
				559	<ul>
				560
				561	<li><tt>list_expression</tt> : An <tt>OrderedList</tt> of code-points.</li>
				562	</ul></li>
				563
				564	<li>Return Value:
				565
				566	<ul>
				567
				568	<li>A <tt>string</tt> representation of <tt>list_expression</tt>.</li>
				569	</ul></li>
				570
				571	<li>
				572	<p>Example:</p>
				573
				574	<div class="source">
				575	<div class="source">
				576	<pre>use dataverse TinySocial;
				577
				578	let $s := "Hello ASTERIX!"
				579	let $l := string-to-codepoint($s)
				580	let $ss := codepoint-to-string($l)
				581	return {"codes": $l, "string": $ss}
				582	</pre></div></div></li>
				583	</ul>
				584
				585	<ul>
				586
				587	<li>
				588	<p>The expected result is:</p>
				589
				590	<div class="source">
				591	<div class="source">
				592	<pre>{ "codes": [ 72, 101, 108, 108, 111, 32, 65, 83, 84, 69, 82, 73, 88, 33 ], "string": "Hello ASTERIX!" }
				593	</pre></div></div></li>
				594	</ul></div>
				595	<div class="section">
				596	<h3><a name="contains"></a>contains</h3>
				597
				598	<ul>
				599
				600	<li>
				601	<p>Syntax:</p>
				602
				603	<div class="source">
				604	<div class="source">
				605	<pre>contains(string_expression, substring_to_contain)
				606	</pre></div></div></li>
				607
				608	<li>
				609	<p>Checks whether the string <tt>string_expression</tt> contains the string <tt>substring_to_contain</tt></p></li>
				610
				611	<li>Arguments:
				612
				613	<ul>
				614
				615	<li><tt>string_expression</tt> : A <tt>string</tt> that might contain the given substring.</li>
				616
				617	<li><tt>substring_to_contain</tt> : A target <tt>string</tt> that might be contained.</li>
				618	</ul></li>
				619
				620	<li>Return Value:
				621
				622	<ul>
				623
				624	<li>A <tt>boolean</tt> value, <tt>true</tt> if <tt>string_expression</tt> contains <tt>substring_to_contain</tt>, and <tt>false</tt> otherwise.</li>
				625	</ul></li>
				626
				627	<li>Note: An <a href="similarity.html#UsingIndexesToSupportSimilarityQueries">n-gram index</a> can be utilized for this function.</li>
				628
				629	<li>
				630	<p>Example:</p>
				631
				632	<div class="source">
				633	<div class="source">
				634	<pre>use dataverse TinySocial;
				635
				636	for $i in dataset('FacebookMessages')
				637	where contains($i.message, "phone")
				638	return {"mid": $i.message-id, "message": $i.message}
				639	</pre></div></div></li>
				640	</ul>
				641
				642	<ul>
				643
				644	<li>
				645	<p>The expected result is:</p>
				646
				647	<div class="source">
				648	<div class="source">
				649	<pre>{ "mid": 2, "message": " dislike iphone its touch-screen is horrible" }
				650	{ "mid": 13, "message": " dislike iphone the voice-command is bad:(" }
				651	{ "mid": 15, "message": " like iphone the voicemail-service is awesome" }
				652	</pre></div></div></li>
				653	</ul></div>
				654	<div class="section">
				655	<h3><a name="like"></a>like</h3>
				656
				657	<ul>
				658
				659	<li>
				660	<p>Syntax:</p>
				661
				662	<div class="source">
				663	<div class="source">
				664	<pre>like(string_expression, string_pattern)
				665	</pre></div></div></li>
				666
				667	<li>
				668	<p>Checks whether the string <tt>string_expression</tt> contains the string pattern <tt>string_pattern</tt>. Compared to the <tt>contains</tt> function, the <tt>like</tt> function also supports regular expressions.</p></li>
				669
				670	<li>Arguments:
				671
				672	<ul>
				673
				674	<li><tt>string_expression</tt> : A <tt>string</tt> that might contain the pattern or <tt>null</tt>.</li>
				675
				676	<li><tt>string_pattern</tt> : A pattern <tt>string</tt> that might be contained or <tt>null</tt>.</li>
				677	</ul></li>
				678
				679	<li>Return Value:
				680
				681	<ul>
				682
				683	<li>A <tt>boolean</tt> value, <tt>true</tt> if <tt>string_expression</tt> contains the pattern <tt>string_pattern</tt>, and <tt>false</tt> otherwise.</li>
				684	</ul></li>
				685
				686	<li>
				687	<p>Example:</p>
				688
				689	<div class="source">
				690	<div class="source">
				691	<pre>use dataverse TinySocial;
				692
				693	for $i in dataset('FacebookMessages')
				694	where like($i.message, "%at&t%")
				695	return $i.message
				696	</pre></div></div></li>
				697	</ul>
				698
				699	<ul>
				700
				701	<li>
				702	<p>The expected result is:</p>
				703
				704	<div class="source">
				705	<div class="source">
				706	<pre>" can't stand at&t the network is horrible:("
				707	" can't stand at&t its plan is terrible"
				708	" love at&t its 3G is good:)"
				709	</pre></div></div></li>
				710	</ul></div>
				711	<div class="section">
				712	<h3><a name="starts-with"></a>starts-with</h3>
				713
				714	<ul>
				715
				716	<li>
				717	<p>Syntax:</p>
				718
				719	<div class="source">
				720	<div class="source">
				721	<pre>starts-with(string_expression, substring_to_start_with)
				722	</pre></div></div></li>
				723
				724	<li>
				725	<p>Checks whether the string <tt>string_expression</tt> starts with the string <tt>substring_to_start_with</tt>.</p></li>
				726
				727	<li>Arguments:
				728
				729	<ul>
				730
				731	<li><tt>string_expression</tt> : A <tt>string</tt> that might start with the given string.</li>
				732
				733	<li><tt>substring_to_start_with</tt> : A <tt>string</tt> that might be contained as the starting substring.</li>
				734	</ul></li>
				735
				736	<li>Return Value:
				737
				738	<ul>
				739
				740	<li>A <tt>boolean</tt>, returns <tt>true</tt> if <tt>string_expression</tt> starts with the string <tt>substring_to_start_with</tt>, and <tt>false</tt> otherwise.</li>
				741	</ul></li>
				742
				743	<li>
				744	<p>Example:</p>
				745
				746	<div class="source">
				747	<div class="source">
				748	<pre>use dataverse TinySocial;
				749
				750	for $i in dataset('FacebookMessages')
				751	where starts-with($i.message, " like")
				752	return $i.message
				753	</pre></div></div></li>
				754	</ul>
				755
				756	<ul>
				757
				758	<li>
				759	<p>The expected result is:</p>
				760
				761	<div class="source">
				762	<div class="source">
				763	<pre>" like samsung the plan is amazing"
				764	" like t-mobile its platform is mind-blowing"
				765	" like verizon the 3G is awesome:)"
				766	" like iphone the voicemail-service is awesome"
				767	</pre></div></div></li>
				768	</ul></div>
				769	<div class="section">
				770	<h3><a name="ends-with"></a>ends-with</h3>
				771
				772	<ul>
				773
				774	<li>
				775	<p>Syntax:</p>
				776
				777	<div class="source">
				778	<div class="source">
				779	<pre>ends-with(string_expression, substring_to_end_with)
				780	</pre></div></div></li>
				781
				782	<li>
				783	<p>Checks whether the string <tt>string_expression</tt> ends with the string <tt>substring_to_end_with</tt>.</p></li>
				784
				785	<li>Arguments:
				786
				787	<ul>
				788
				789	<li><tt>string_expression</tt> : A <tt>string</tt> that might end with the given string.</li>
				790
				791	<li><tt>substring_to_end_with</tt> : A <tt>string</tt> that might be contained as the ending substring.</li>
				792	</ul></li>
				793
				794	<li>Return Value:
				795
				796	<ul>
				797
				798	<li>A <tt>boolean</tt>, returns <tt>true</tt> if <tt>string_expression</tt> ends with the string <tt>substring_to_end_with</tt>, and <tt>false</tt> otherwise.</li>
				799	</ul></li>
				800
				801	<li>
				802	<p>Example:</p>
				803
				804	<div class="source">
				805	<div class="source">
				806	<pre>use dataverse TinySocial;
				807
				808	for $i in dataset('FacebookMessages')
				809	where ends-with($i.message, ":)")
				810	return $i.message
				811	</pre></div></div></li>
				812	</ul>
				813
				814	<ul>
				815
				816	<li>
				817	<p>The expected result is:</p>
				818
				819	<div class="source">
				820	<div class="source">
				821	<pre>" love sprint its shortcut-menu is awesome:)"
				822	" like verizon the 3G is awesome:)"
				823	" love at&t its 3G is good:)"
				824	</pre></div></div></li>
				825	</ul></div>
				826	<div class="section">
				827	<h3><a name="string-concat"></a>string-concat</h3>
				828
				829	<ul>
				830
				831	<li>
				832	<p>Syntax:</p>
				833
				834	<div class="source">
				835	<div class="source">
				836	<pre>string-concat(list_expression)
				837	</pre></div></div></li>
				838
				839	<li>
				840	<p>Concatenates a list of strings <tt>list_expression</tt> into a single string.</p></li>
				841
				842	<li>Arguments:
				843
				844	<ul>
				845
				846	<li><tt>list_expression</tt> : An <tt>OrderedList</tt> or <tt>UnorderedList</tt> of <tt>string</tt>s (could be <tt>null</tt>) to be concatenated.</li>
				847	</ul></li>
				848
				849	<li>Return Value:
				850
				851	<ul>
				852
				853	<li>Returns the concatenated <tt>string</tt> value.</li>
				854	</ul></li>
				855
				856	<li>
				857	<p>Example:</p>
				858
				859	<div class="source">
				860	<div class="source">
				861	<pre>let $i := "ASTERIX"
				862	let $j := " "
				863	let $k := "ROCKS!"
				864	return string-concat([$i, $j, $k])
				865	</pre></div></div></li>
				866	</ul>
				867
				868	<ul>
				869
				870	<li>
				871	<p>The expected result is:</p>
				872
				873	<div class="source">
				874	<div class="source">
				875	<pre>"ASTERIX ROCKS!"
				876	</pre></div></div></li>
				877	</ul></div>
				878	<div class="section">
				879	<h3><a name="string-join"></a>string-join</h3>
				880
				881	<ul>
				882
				883	<li>
				884	<p>Syntax:</p>
				885
				886	<div class="source">
				887	<div class="source">
				888	<pre>string-join(list_expression, string_expression)
				889	</pre></div></div></li>
				890
				891	<li>
				892	<p>Joins a list of strings <tt>list_expression</tt> with the given separator <tt>string_expression</tt> into a single string.</p></li>
				893
				894	<li>Arguments:
				895
				896	<ul>
				897
				898	<li><tt>list_expression</tt> : An <tt>OrderedList</tt> or <tt>UnorderedList</tt> of strings (could be <tt>null</tt>) to be joined.</li>
				899
				900	<li><tt>string_expression</tt> : A <tt>string</tt> as the separator.</li>
				901	</ul></li>
				902
				903	<li>Return Value:
				904
				905	<ul>
				906
				907	<li>Returns the joined <tt>String</tt>.</li>
				908	</ul></li>
				909
				910	<li>
				911	<p>Example:</p>
				912
				913	<div class="source">
				914	<div class="source">
				915	<pre>use dataverse TinySocial;
				916
				917	let $i := ["ASTERIX", "ROCKS~"]
				918	return string-join($i, "!! ")
				919	</pre></div></div></li>
				920	</ul>
				921
				922	<ul>
				923
				924	<li>
				925	<p>The expected result is:</p>
				926
				927	<div class="source">
				928	<div class="source">
				929	<pre>"ASTERIX!! ROCKS~"
				930	</pre></div></div></li>
				931	</ul></div>
				932	<div class="section">
				933	<h3><a name="lowercase"></a>lowercase</h3>
				934
				935	<ul>
				936
				937	<li>
				938	<p>Syntax:</p>
				939
				940	<div class="source">
				941	<div class="source">
				942	<pre>lowercase(string_expression)
				943	</pre></div></div></li>
				944
				945	<li>
				946	<p>Converts a given string <tt>string_expression</tt> to its lowercase form.</p></li>
				947
				948	<li>Arguments:
				949
				950	<ul>
				951
				952	<li><tt>string_expression</tt> : A <tt>string</tt> to be converted.</li>
				953	</ul></li>
				954
				955	<li>Return Value:
				956
				957	<ul>
				958
				959	<li>Returns a <tt>string</tt> as the lowercase form of the given <tt>string_expression</tt>.</li>
				960	</ul></li>
				961
				962	<li>
				963	<p>Example:</p>
				964
				965	<div class="source">
				966	<div class="source">
				967	<pre>use dataverse TinySocial;
				968
				969	let $i := "ASTERIX"
				970	return lowercase($i)
				971	</pre></div></div></li>
				972	</ul>
				973
				974	<ul>
				975
				976	<li>
				977	<p>The expected result is:</p>
				978
				979	<div class="source">
				980	<div class="source">
				981	<pre>asterix
				982	</pre></div></div></li>
				983	</ul></div>
				984	<div class="section">
				985	<h3><a name="uppercase"></a>uppercase</h3>
				986
				987	<ul>
				988
				989	<li>Syntax:</li>
				990	</ul>
				991	<p>uppercase(string_expression)</p>
				992
				993	<ul>
				994
				995	<li>Converts a given string <tt>string_expression</tt> to its uppercase form.</li>
				996
				997	<li>Arguments:
				998
				999	<ul>
				1000
				1001	<li><tt>string_expression</tt> : A <tt>string</tt> to be converted.</li>
				1002	</ul></li>
				1003
				1004	<li>Return Value:
				1005
				1006	<ul>
				1007
				1008	<li>Returns a <tt>string</tt> as the uppercase form of the given <tt>string_expression</tt>.</li>
				1009	</ul></li>
				1010
				1011	<li>
				1012	<p>Example:</p>
				1013
				1014	<div class="source">
				1015	<div class="source">
				1016	<pre>use dataverse TinySocial;
				1017
				1018	let $i := "asterix"
				1019	return uppercase($i)
				1020	</pre></div></div></li>
				1021	</ul>
				1022
				1023	<ul>
				1024
				1025	<li>
				1026	<p>The expected result is:</p>
				1027
				1028	<div class="source">
				1029	<div class="source">
				1030	<pre>ASTERIX
				1031	</pre></div></div></li>
				1032	</ul></div>
				1033	<div class="section">
				1034	<h3><a name="uppercase"></a>uppercase</h3>
				1035
				1036	<ul>
				1037
				1038	<li>
				1039	<p>Syntax:</p>
				1040
				1041	<div class="source">
				1042	<div class="source">
				1043	<pre>uppercase(string_expression)
				1044	</pre></div></div></li>
				1045
				1046	<li>
				1047	<p>Converts a given string <tt>string_expression</tt> to its uppercase form.</p></li>
				1048
				1049	<li>Arguments:
				1050
				1051	<ul>
				1052
				1053	<li><tt>string_expression</tt> : A <tt>string</tt> to be converted.</li>
				1054	</ul></li>
				1055
				1056	<li>Return Value:
				1057
				1058	<ul>
				1059
				1060	<li>Returns a <tt>string</tt> as the uppercase form of the given <tt>string_expression</tt>.</li>
				1061	</ul></li>
				1062
				1063	<li>
				1064	<p>Example:</p>
				1065
				1066	<div class="source">
				1067	<div class="source">
				1068	<pre>use dataverse TinySocial;
				1069
				1070	let $i := "asterix"
				1071	return uppercase($i)
				1072	</pre></div></div></li>
				1073	</ul>
				1074
				1075	<ul>
				1076
				1077	<li>
				1078	<p>The expected result is:</p>
				1079
				1080	<div class="source">
				1081	<div class="source">
				1082	<pre>ASTERIX
				1083	</pre></div></div></li>
				1084	</ul></div>
				1085	<div class="section">
				1086	<h3><a name="matches"></a>matches</h3>
				1087
				1088	<ul>
				1089
				1090	<li>
				1091	<p>Syntax:</p>
				1092
				1093	<div class="source">
				1094	<div class="source">
				1095	<pre>matches(string_expression, string_pattern)
				1096	</pre></div></div></li>
				1097
				1098	<li>
				1099	<p>Checks whether the strings <tt>string_expression</tt> matches the given pattern <tt>string_pattern</tt> (A Java regular expression pattern).</p></li>
				1100
				1101	<li>Arguments:
				1102
				1103	<ul>
				1104
				1105	<li><tt>string_expression</tt> : A <tt>string</tt> that might contain the pattern.</li>
				1106
				1107	<li><tt>string_pattern</tt> : A pattern <tt>string</tt> to be matched.</li>
				1108	</ul></li>
				1109
				1110	<li>Return Value:
				1111
				1112	<ul>
				1113
				1114	<li>A <tt>boolean</tt>, returns <tt>true</tt> if <tt>string_expression</tt> matches the pattern <tt>string_pattern</tt>, and <tt>false</tt> otherwise.</li>
				1115	</ul></li>
				1116
				1117	<li>
				1118	<p>Example:</p>
				1119
				1120	<div class="source">
				1121	<div class="source">
				1122	<pre>use dataverse TinySocial;
				1123
				1124	for $i in dataset('FacebookMessages')
				1125	where matches($i.message, "dislike iphone")
				1126	return $i.message
				1127	</pre></div></div></li>
				1128	</ul>
				1129
				1130	<ul>
				1131
				1132	<li>
				1133	<p>The expected result is:</p>
				1134
				1135	<div class="source">
				1136	<div class="source">
				1137	<pre>" dislike iphone its touch-screen is horrible"
				1138	" dislike iphone the voice-command is bad:("
				1139	</pre></div></div></li>
				1140	</ul></div>
				1141	<div class="section">
				1142	<h3><a name="replace"></a>replace</h3>
				1143
				1144	<ul>
				1145
				1146	<li>
				1147	<p>Syntax:</p>
				1148
				1149	<div class="source">
				1150	<div class="source">
				1151	<pre>replace(string_expression, string_pattern, string_replacement[, string_flags])
				1152	</pre></div></div></li>
				1153
				1154	<li>
				1155	<p>Checks whether the string <tt>string_expression</tt> matches the given pattern <tt>string_pattern</tt>, and replace the matched pattern <tt>string_pattern</tt> with the new pattern <tt>string_replacement</tt>.</p></li>
				1156
				1157	<li>Arguments:
				1158
				1159	<ul>
				1160
				1161	<li><tt>string_expression</tt> : A <tt>string</tt> that might contain the pattern.</li>
				1162
				1163	<li><tt>string_pattern</tt> : A pattern <tt>string</tt> to be matched.</li>
				1164
				1165	<li><tt>string_replacement</tt> : A pattern <tt>string</tt> to be used as the replacement.</li>
				1166
				1167	<li><tt>string_flag</tt> : (Optional) A <tt>string</tt> with flags to be used during replace.</li>
				1168
				1169	<li>The following modes are enabled with these flags: dotall (s), multiline (m), case-insenitive (i), and comments and whitespace (x).</li>
				1170	</ul></li>
				1171
				1172	<li>Return Value:
				1173
				1174	<ul>
				1175
				1176	<li>Returns a <tt>string</tt> that is obtained after the replacements.</li>
				1177	</ul></li>
				1178
				1179	<li>
				1180	<p>Example:</p>
				1181
				1182	<div class="source">
				1183	<div class="source">
				1184	<pre>use dataverse TinySocial;
				1185
				1186	for $i in dataset('FacebookMessages')
				1187	where matches($i.message, " like iphone")
				1188	return replace($i.message, " like iphone", "like android")
				1189	</pre></div></div></li>
				1190	</ul>
				1191
				1192	<ul>
				1193
				1194	<li>
				1195	<p>The expected result is:</p>
				1196
				1197	<div class="source">
				1198	<div class="source">
				1199	<pre>"like android the voicemail-service is awesome"
				1200	</pre></div></div></li>
				1201	</ul></div>
				1202	<div class="section">
				1203	<h3><a name="string-length"></a>string-length</h3>
				1204
				1205	<ul>
				1206
				1207	<li>
				1208	<p>Syntax:</p>
				1209
				1210	<div class="source">
				1211	<div class="source">
				1212	<pre>string-length(string_expression)
				1213	</pre></div></div></li>
				1214
				1215	<li>
				1216	<p>Returns the length of the string <tt>string_expression</tt>.</p></li>
				1217
				1218	<li>Arguments:
				1219
				1220	<ul>
				1221
				1222	<li><tt>string_expression</tt> : A <tt>string</tt> or <tt>null</tt> that represents the string to be checked.</li>
				1223	</ul></li>
				1224
				1225	<li>Return Value:
				1226
				1227	<ul>
				1228
				1229	<li>An <tt>int64</tt> that represents the length of <tt>string_expression</tt>.</li>
				1230	</ul></li>
				1231
				1232	<li>
				1233	<p>Example:</p>
				1234
				1235	<div class="source">
				1236	<div class="source">
				1237	<pre>use dataverse TinySocial;
				1238
				1239	for $i in dataset('FacebookMessages')
				1240	return {"mid": $i.message-id, "message-len": string-length($i.message)}
				1241	</pre></div></div></li>
				1242	</ul>
				1243
				1244	<ul>
				1245
				1246	<li>
				1247	<p>The expected result is:</p>
				1248
				1249	<div class="source">
				1250	<div class="source">
				1251	<pre>{ "mid": 1, "message-len": 43 }
				1252	{ "mid": 2, "message-len": 44 }
				1253	{ "mid": 3, "message-len": 33 }
				1254	{ "mid": 4, "message-len": 43 }
				1255	{ "mid": 5, "message-len": 46 }
				1256	{ "mid": 6, "message-len": 43 }
				1257	{ "mid": 7, "message-len": 37 }
				1258	{ "mid": 8, "message-len": 33 }
				1259	{ "mid": 9, "message-len": 34 }
				1260	{ "mid": 10, "message-len": 50 }
				1261	{ "mid": 11, "message-len": 38 }
				1262	{ "mid": 12, "message-len": 52 }
				1263	{ "mid": 13, "message-len": 42 }
				1264	{ "mid": 14, "message-len": 27 }
				1265	{ "mid": 15, "message-len": 45 }
				1266	</pre></div></div></li>
				1267	</ul></div>
				1268	<div class="section">
				1269	<h3><a name="substring"></a>substring</h3>
				1270
				1271	<ul>
				1272
				1273	<li>
				1274	<p>Syntax:</p>
				1275
				1276	<div class="source">
				1277	<div class="source">
				1278	<pre>substring(string_expression, offset[, length])
				1279	</pre></div></div></li>
				1280
				1281	<li>
				1282	<p>Returns the substring from the given string <tt>string_expression</tt> based on the given start offset <tt>offset</tt> with the optional <tt>length</tt>.</p></li>
				1283
				1284	<li>Arguments:
				1285
				1286	<ul>
				1287
				1288	<li><tt>string_expression</tt> : A <tt>string</tt> to be extracted.</li>
				1289
				1290	<li><tt>offset</tt> : An <tt>int64</tt> as the starting offset of the substring in <tt>string_expression</tt>.</li>
				1291
				1292	<li><tt>length</tt> : (Optional) An <tt>int64</tt> as the length of the substring.</li>
				1293	</ul></li>
				1294
				1295	<li>Return Value:
				1296
				1297	<ul>
				1298
				1299	<li>A <tt>string</tt> that represents the substring.</li>
				1300	</ul></li>
				1301
				1302	<li>
				1303	<p>Example:</p>
				1304
				1305	<div class="source">
				1306	<div class="source">
				1307	<pre>use dataverse TinySocial;
				1308
				1309	for $i in dataset('FacebookMessages')
				1310	where string-length($i.message) > 50
				1311	return substring($i.message, 50)
				1312	</pre></div></div></li>
				1313	</ul>
				1314
				1315	<ul>
				1316
				1317	<li>
				1318	<p>The expected result is:</p>
				1319
				1320	<div class="source">
				1321	<div class="source">
				1322	<pre>"G:("
				1323	</pre></div></div></li>
				1324	</ul></div>
				1325	<div class="section">
				1326	<h3><a name="substring-before"></a>substring-before</h3>
				1327
				1328	<ul>
				1329
				1330	<li>
				1331	<p>Syntax:</p>
				1332
				1333	<div class="source">
				1334	<div class="source">
				1335	<pre>substring-before(string_expression, string_pattern)
				1336	</pre></div></div></li>
				1337
				1338	<li>
				1339	<p>Returns the substring from the given string <tt>string_expression</tt> before the given pattern <tt>string_pattern</tt>.</p></li>
				1340
				1341	<li>Arguments:
				1342
				1343	<ul>
				1344
				1345	<li><tt>string_expression</tt> : A <tt>string</tt> to be extracted.</li>
				1346
				1347	<li><tt>string_pattern</tt> : A <tt>string</tt> pattern to be searched.</li>
				1348	</ul></li>
				1349
				1350	<li>Return Value:
				1351
				1352	<ul>
				1353
				1354	<li>A <tt>string</tt> that represents the substring.</li>
				1355	</ul></li>
				1356
				1357	<li>
				1358	<p>Example:</p>
				1359
				1360	<div class="source">
				1361	<div class="source">
				1362	<pre>use dataverse TinySocial;
				1363
				1364	for $i in dataset('FacebookMessages')
				1365	where contains($i.message, "iphone")
				1366	return substring-before($i.message, "iphone")
				1367	</pre></div></div></li>
				1368	</ul>
				1369
				1370	<ul>
				1371
				1372	<li>
				1373	<p>The expected result is:</p>
				1374
				1375	<div class="source">
				1376	<div class="source">
				1377	<pre>" dislike "
				1378	" dislike "
				1379	" like "
				1380	</pre></div></div></li>
				1381	</ul></div>
				1382	<div class="section">
				1383	<h3><a name="substring-after"></a>substring-after</h3>
				1384
				1385	<ul>
				1386
				1387	<li>
				1388	<p>Syntax:</p>
				1389
				1390	<div class="source">
				1391	<div class="source">
				1392	<pre>substring-after(string_expression, string_pattern)
				1393	</pre></div></div></li>
				1394
				1395	<li>
				1396	<p>Returns the substring from the given string <tt>string_expression</tt> after the given pattern <tt>string_pattern</tt>.</p></li>
				1397
				1398	<li>Arguments:
				1399
				1400	<ul>
				1401
				1402	<li><tt>string_expression</tt> : A <tt>string</tt> to be extracted.</li>
				1403
				1404	<li><tt>string_pattern</tt> : A <tt>string</tt> pattern to be searched.</li>
				1405	</ul></li>
				1406
				1407	<li>Return Value:
				1408
				1409	<ul>
				1410
				1411	<li>A <tt>string</tt> that represents the substring.</li>
				1412	</ul></li>
				1413
				1414	<li>
				1415	<p>Example:</p>
				1416
				1417	<div class="source">
				1418	<div class="source">
				1419	<pre>use dataverse TinySocial;
				1420
				1421	for $i in dataset('FacebookMessages')
				1422	where contains($i.message, "iphone")
				1423	return substring-after($i.message, "iphone")
				1424	</pre></div></div></li>
				1425	</ul>
				1426
				1427	<ul>
				1428
				1429	<li>
				1430	<p>The expected result is:</p>
				1431
				1432	<div class="source">
				1433	<div class="source">
				1434	<pre>" its touch-screen is horrible"
				1435	" the voice-command is bad:("
				1436	" the voicemail-service is awesome"
				1437	</pre></div></div></li>
				1438	</ul></div></div>
				1439	<div class="section">
				1440	<h2><a name="Aggregate_Functions_Back_to_TOC"></a><a name="AggregateFunctions" id="AggregateFunctions">Aggregate Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				1441	<div class="section">
				1442	<h3><a name="count"></a>count</h3>
				1443
				1444	<ul>
				1445
				1446	<li>
				1447	<p>Syntax:</p>
				1448
				1449	<div class="source">
				1450	<div class="source">
				1451	<pre>count(list)
				1452	</pre></div></div></li>
				1453
				1454	<li>
				1455	<p>Gets the number of items in the given list.</p></li>
				1456
				1457	<li>Arguments:
				1458
				1459	<ul>
				1460
				1461	<li><tt>list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing the items to be counted, or a <tt>null</tt> value.</li>
				1462	</ul></li>
				1463
				1464	<li>Return Value:
				1465
				1466	<ul>
				1467
				1468	<li>An <tt>int64</tt> value representing the number of items in the given list. <tt>0i64</tt> is returned if the input is <tt>null</tt>.</li>
				1469	</ul></li>
				1470
				1471	<li>
				1472	<p>Example:</p>
				1473
				1474	<div class="source">
				1475	<div class="source">
				1476	<pre>use dataverse TinySocial;
				1477
				1478	let $l1 := ['hello', 'world', 1, 2, 3]
				1479	let $l2 := for $i in dataset TwitterUsers return $i
				1480	return {"count1": count($l1), "count2": count($l2)}
				1481	</pre></div></div></li>
				1482
				1483	<li>
				1484	<p>The expected result is:</p>
				1485
				1486	<div class="source">
				1487	<div class="source">
				1488	<pre>{ "count1": 5i64, "count2": 4i64 }
				1489	</pre></div></div></li>
				1490	</ul></div>
				1491	<div class="section">
				1492	<h3><a name="avg"></a>avg</h3>
				1493
				1494	<ul>
				1495
				1496	<li>
				1497	<p>Syntax:</p>
				1498
				1499	<div class="source">
				1500	<div class="source">
				1501	<pre>avg(num_list)
				1502	</pre></div></div></li>
				1503
				1504	<li>
				1505	<p>Gets the average value of the items in the given list.</p></li>
				1506
				1507	<li>Arguments:
				1508
				1509	<ul>
				1510
				1511	<li><tt>num_list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing numeric or null values, or a <tt>null</tt> value.</li>
				1512	</ul></li>
				1513
				1514	<li>Return Value:
				1515
				1516	<ul>
				1517
				1518	<li>An <tt>double</tt> value representing the average of the numbers in the given list. <tt>null</tt> is returned if the input is <tt>null</tt>, or the input list contains <tt>null</tt>. Non-numeric types in the input list will cause an error.</li>
				1519	</ul></li>
				1520
				1521	<li>
				1522	<p>Example:</p>
				1523
				1524	<div class="source">
				1525	<div class="source">
				1526	<pre>use dataverse TinySocial;
				1527
				1528	let $l := for $i in dataset TwitterUsers return $i.friends_count
				1529	return {"avg_friend_count": avg($l)}
				1530	</pre></div></div></li>
				1531
				1532	<li>
				1533	<p>The expected result is:</p>
				1534
				1535	<div class="source">
				1536	<div class="source">
				1537	<pre>{ "avg_friend_count": 191.5d }
				1538	</pre></div></div></li>
				1539	</ul></div>
				1540	<div class="section">
				1541	<h3><a name="sum"></a>sum</h3>
				1542
				1543	<ul>
				1544
				1545	<li>
				1546	<p>Syntax:</p>
				1547
				1548	<div class="source">
				1549	<div class="source">
				1550	<pre>sum(num_list)
				1551	</pre></div></div></li>
				1552
				1553	<li>
				1554	<p>Gets the sum of the items in the given list.</p></li>
				1555
				1556	<li>Arguments:
				1557
				1558	<ul>
				1559
				1560	<li><tt>num_list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing numeric or null values, or a <tt>null</tt> value.</li>
				1561	</ul></li>
				1562
				1563	<li>Return Value:
				1564
				1565	<ul>
				1566
				1567	<li>The sum of the numbers in the given list. The returning type is decided by the item type with the highest order in the numeric type promotion order (<tt>int8</tt>-> <tt>int16</tt>-><tt>int32</tt>-><tt>int64</tt>-><tt>float</tt>-><tt>double</tt>) among items. <tt>null</tt> is returned if the input is <tt>null</tt>, or the input list contains <tt>null</tt>. Non-numeric types in the input list will cause an error.</li>
				1568	</ul></li>
				1569
				1570	<li>
				1571	<p>Example:</p>
				1572
				1573	<div class="source">
				1574	<div class="source">
				1575	<pre>use dataverse TinySocial;
				1576
				1577	let $l := for $i in dataset TwitterUsers return $i.friends_count
				1578	return {"sum_friend_count": sum($l)}
				1579	</pre></div></div></li>
				1580
				1581	<li>
				1582	<p>The expected result is:</p>
				1583
				1584	<div class="source">
				1585	<div class="source">
				1586	<pre>{ "sum_friend_count": 766 }
				1587	</pre></div></div></li>
				1588	</ul></div>
				1589	<div class="section">
				1590	<h3><a name="minmax"></a>min/max</h3>
				1591
				1592	<ul>
				1593
				1594	<li>
				1595	<p>Syntax:</p>
				1596
				1597	<div class="source">
				1598	<div class="source">
				1599	<pre>min(num_list), max(num_list)
				1600	</pre></div></div></li>
				1601
				1602	<li>
				1603	<p>Gets the min/max value of numeric items in the given list.</p></li>
				1604
				1605	<li>Arguments:
				1606
				1607	<ul>
				1608
				1609	<li><tt>num_list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing the items to be compared, or a <tt>null</tt> value.</li>
				1610	</ul></li>
				1611
				1612	<li>Return Value:
				1613
				1614	<ul>
				1615
				1616	<li>The min/max value of the given list. The returning type is decided by the item type with the highest order in the numeric type promotion order (<tt>int8</tt>-> <tt>int16</tt>-><tt>int32</tt>-><tt>int64</tt>-><tt>float</tt>-><tt>double</tt>) among items. <tt>null</tt> is returned if the input is <tt>null</tt>, or the input list contains <tt>null</tt>. Non-numeric types in the input list will cause an error.</li>
				1617	</ul></li>
				1618
				1619	<li>
				1620	<p>Example:</p>
				1621
				1622	<div class="source">
				1623	<div class="source">
				1624	<pre>use dataverse TinySocial;
				1625
				1626	let $l := for $i in dataset TwitterUsers return $i. friends_count
				1627	return {"min_friend_count": min($l), "max_friend_count": max($l)}
				1628	</pre></div></div></li>
				1629
				1630	<li>
				1631	<p>The expected result is:</p>
				1632
				1633	<div class="source">
				1634	<div class="source">
				1635	<pre>{ "min_friend_count": 18, "max_friend_count": 445 }
				1636	</pre></div></div></li>
				1637	</ul></div>
				1638	<div class="section">
				1639	<h3><a name="sql-count"></a>sql-count</h3>
				1640
				1641	<ul>
				1642
				1643	<li>
				1644	<p>Syntax:</p>
				1645
				1646	<div class="source">
				1647	<div class="source">
				1648	<pre>sql-count(list)
				1649	</pre></div></div></li>
				1650
				1651	<li>
				1652	<p>Gets the number of non-null items in the given list.</p></li>
				1653
				1654	<li>Arguments:
				1655
				1656	<ul>
				1657
				1658	<li><tt>list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing the items to be counted, or a <tt>null</tt> value.</li>
				1659	</ul></li>
				1660
				1661	<li>Return Value:
				1662
				1663	<ul>
				1664
				1665	<li>An <tt>int64</tt> value representing the number of non-null items in the given list. The value <tt>0i64</tt> is returned if the input is <tt>null</tt>.</li>
				1666	</ul></li>
				1667
				1668	<li>
				1669	<p>Example:</p></li>
				1670	</ul>
				1671
				1672	<div class="source">
				1673	<div class="source">
				1674	<pre> let $l1 := ['hello', 'world', 1, 2, 3, null]
				1675	return {"count": sql-count($l1)}
				1676	</pre></div></div>
				1677
				1678	<ul>
				1679
				1680	<li>
				1681	<p>The expected result is:</p>
				1682
				1683	<div class="source">
				1684	<div class="source">
				1685	<pre>{ "count": 5i64 }
				1686	</pre></div></div></li>
				1687	</ul></div>
				1688	<div class="section">
				1689	<h3><a name="sql-avg"></a>sql-avg</h3>
				1690
				1691	<ul>
				1692
				1693	<li>
				1694	<p>Syntax:</p>
				1695
				1696	<div class="source">
				1697	<div class="source">
				1698	<pre>sql-avg(num_list)
				1699	</pre></div></div></li>
				1700
				1701	<li>
				1702	<p>Gets the average value of the non-null items in the given list.</p></li>
				1703
				1704	<li>Arguments:
				1705
				1706	<ul>
				1707
				1708	<li><tt>num_list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing numeric or null values, or a <tt>null</tt> value.</li>
				1709	</ul></li>
				1710
				1711	<li>Return Value:
				1712
				1713	<ul>
				1714
				1715	<li>A <tt>double</tt> value representing the average of the non-null numbers in the given list. The <tt>null</tt> value is returned if the input is <tt>null</tt>. Non-numeric types in the input list will cause an error.</li>
				1716	</ul></li>
				1717
				1718	<li>
				1719	<p>Example:</p>
				1720
				1721	<div class="source">
				1722	<div class="source">
				1723	<pre>let $l := [1.2, 2.3, 3.4, 0, null]
				1724	return {"avg": sql-avg($l)}
				1725	</pre></div></div></li>
				1726
				1727	<li>
				1728	<p>The expected result is:</p>
				1729
				1730	<div class="source">
				1731	<div class="source">
				1732	<pre>{ "avg": 1.725d }
				1733	</pre></div></div></li>
				1734	</ul></div>
				1735	<div class="section">
				1736	<h3><a name="sql-sum"></a>sql-sum</h3>
				1737
				1738	<ul>
				1739
				1740	<li>
				1741	<p>Syntax:</p>
				1742
				1743	<div class="source">
				1744	<div class="source">
				1745	<pre>sql-sum(num_list)
				1746	</pre></div></div></li>
				1747
				1748	<li>
				1749	<p>Gets the sum of the non-null items in the given list.</p></li>
				1750
				1751	<li>Arguments:
				1752
				1753	<ul>
				1754
				1755	<li><tt>num_list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing numeric or null values, or a <tt>null</tt> value.</li>
				1756	</ul></li>
				1757
				1758	<li>Return Value:
				1759
				1760	<ul>
				1761
				1762	<li>The sum of the non-null numbers in the given list. The returning type is decided by the item type with the highest order in the numeric type promotion order (<tt>int8</tt>-> <tt>int16</tt>-><tt>int32</tt>-><tt>int64</tt>-><tt>float</tt>-><tt>double</tt>) among items. The value <tt>null</tt> is returned if the input is <tt>null</tt>. Non-numeric types in the input list will cause an error.</li>
				1763	</ul></li>
				1764
				1765	<li>
				1766	<p>Example:</p>
				1767
				1768	<div class="source">
				1769	<div class="source">
				1770	<pre>let $l := [1.2, 2.3, 3.4, 0, null]
				1771	return {"sum": sql-sum($l)}
				1772	</pre></div></div></li>
				1773
				1774	<li>
				1775	<p>The expected result is:</p>
				1776
				1777	<div class="source">
				1778	<div class="source">
				1779	<pre>{ "sum": 6.9d }
				1780	</pre></div></div></li>
				1781	</ul></div>
				1782	<div class="section">
				1783	<h3><a name="sql-minmax"></a>sql-min/max</h3>
				1784
				1785	<ul>
				1786
				1787	<li>
				1788	<p>Syntax:</p>
				1789
				1790	<div class="source">
				1791	<div class="source">
				1792	<pre>sql-min(num_list), sql-max(num_list)
				1793	</pre></div></div></li>
				1794
				1795	<li>
				1796	<p>Gets the min/max value of the non-null numeric items in the given list.</p></li>
				1797
				1798	<li>Arguments:
				1799
				1800	<ul>
				1801
				1802	<li><tt>num_list</tt>: An <tt>orderedList</tt> or <tt>unorderedList</tt> containing the items to be compared, or a <tt>null</tt> value.</li>
				1803	</ul></li>
				1804
				1805	<li>Return Value:
				1806
				1807	<ul>
				1808
				1809	<li>The min/max value of the given list. The returning type is decided by the item type with the highest order in the numeric type promotion order (<tt>int8</tt>-> <tt>int16</tt>-><tt>int32</tt>-><tt>int64</tt>-><tt>float</tt>-><tt>double</tt>) among items. The value <tt>null</tt> is returned if the input is <tt>null</tt>. Non-numeric types in the input list will cause an error.</li>
				1810	</ul></li>
				1811
				1812	<li>
				1813	<p>Example:</p>
				1814
				1815	<div class="source">
				1816	<div class="source">
				1817	<pre>let $l := [1.2, 2.3, 3.4, 0, null]
				1818	return {"min": sql-min($l), "max": sql-max($l)}
				1819	</pre></div></div></li>
				1820
				1821	<li>
				1822	<p>The expected result is:</p>
				1823
				1824	<div class="source">
				1825	<div class="source">
				1826	<pre>{ "min": 0.0d, "max": 3.4d }
				1827	</pre></div></div></li>
				1828	</ul></div></div>
				1829	<div class="section">
				1830	<h2><a name="Spatial_Functions_Back_to_TOC"></a><a name="SpatialFunctions" id="SpatialFunctions">Spatial Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				1831	<div class="section">
				1832	<h3><a name="create-point"></a>create-point</h3>
				1833
				1834	<ul>
				1835
				1836	<li>
				1837	<p>Syntax:</p>
				1838
				1839	<div class="source">
				1840	<div class="source">
				1841	<pre>create-point(x, y)
				1842	</pre></div></div></li>
				1843
				1844	<li>
				1845	<p>Creates the primitive type <tt>point</tt> using an <tt>x</tt> and <tt>y</tt> value.</p></li>
				1846
				1847	<li>Arguments:</li>
				1848
				1849	<li><tt>x</tt> : A <tt>double</tt> that represents the x-coordinate.</li>
				1850
				1851	<li><tt>y</tt> : A <tt>double</tt> that represents the y-coordinate.</li>
				1852
				1853	<li>Return Value:</li>
				1854
				1855	<li>A <tt>point</tt> representing the ordered pair (<tt>x</tt>, <tt>y</tt>).</li>
				1856
				1857	<li>
				1858	<p>Example:</p>
				1859
				1860	<div class="source">
				1861	<div class="source">
				1862	<pre>use dataverse TinySocial;
				1863
				1864	let $c := create-point(30.0,70.0)
				1865	return {"point": $c}
				1866	</pre></div></div></li>
				1867	</ul>
				1868
				1869	<ul>
				1870
				1871	<li>
				1872	<p>The expected result is:</p>
				1873
				1874	<div class="source">
				1875	<div class="source">
				1876	<pre>{ "point": point("30.0,70.0") }
				1877	</pre></div></div></li>
				1878	</ul></div>
				1879	<div class="section">
				1880	<h3><a name="create-line"></a>create-line</h3>
				1881
				1882	<ul>
				1883
				1884	<li>
				1885	<p>Syntax:</p>
				1886
				1887	<div class="source">
				1888	<div class="source">
				1889	<pre>create-line(point_expression1, point_expression2)
				1890	</pre></div></div></li>
				1891
				1892	<li>
				1893	<p>Creates the primitive type <tt>line</tt> using <tt>point_expression1</tt> and <tt>point_expression2</tt>.</p></li>
				1894
				1895	<li>Arguments:
				1896
				1897	<ul>
				1898
				1899	<li><tt>point_expression1</tt> : A <tt>point</tt> that represents the start point of the line.</li>
				1900
				1901	<li><tt>point_expression2</tt> : A <tt>point</tt> that represents the end point of the line.</li>
				1902	</ul></li>
				1903
				1904	<li>Return Value:
				1905
				1906	<ul>
				1907
				1908	<li>A spatial <tt>line</tt> created using the points provided in <tt>point_expression1</tt> and <tt>point_expression2</tt>.</li>
				1909	</ul></li>
				1910
				1911	<li>
				1912	<p>Example:</p>
				1913
				1914	<div class="source">
				1915	<div class="source">
				1916	<pre>use dataverse TinySocial;
				1917
				1918	let $c := create-line(create-point(30.0,70.0), create-point(50.0,90.0))
				1919	return {"line": $c}
				1920	</pre></div></div></li>
				1921	</ul>
				1922
				1923	<ul>
				1924
				1925	<li>
				1926	<p>The expected result is:</p>
				1927
				1928	<div class="source">
				1929	<div class="source">
				1930	<pre>{ "line": line("30.0,70.0 50.0,90.0") }
				1931	</pre></div></div></li>
				1932	</ul></div>
				1933	<div class="section">
				1934	<h3><a name="create-rectangle"></a>create-rectangle</h3>
				1935
				1936	<ul>
				1937
				1938	<li>
				1939	<p>Syntax:</p>
				1940
				1941	<div class="source">
				1942	<div class="source">
				1943	<pre>create-rectangle(point_expression1, point_expression2)
				1944	</pre></div></div></li>
				1945
				1946	<li>
				1947	<p>Creates the primitive type <tt>rectangle</tt> using <tt>point_expression1</tt> and <tt>point_expression2</tt>.</p></li>
				1948
				1949	<li>Arguments:
				1950
				1951	<ul>
				1952
				1953	<li><tt>point_expression1</tt> : A <tt>point</tt> that represents the lower-left point of the rectangle.</li>
				1954
				1955	<li><tt>point_expression2</tt> : A <tt>point</tt> that represents the upper-right point of the rectangle.</li>
				1956	</ul></li>
				1957
				1958	<li>Return Value:
				1959
				1960	<ul>
				1961
				1962	<li>A spatial <tt>rectangle</tt> created using the points provided in <tt>point_expression1</tt> and <tt>point_expression2</tt>.</li>
				1963	</ul></li>
				1964
				1965	<li>
				1966	<p>Example:</p>
				1967
				1968	<div class="source">
				1969	<div class="source">
				1970	<pre>use dataverse TinySocial;
				1971
				1972	let $c := create-rectangle(create-point(30.0,70.0), create-point(50.0,90.0))
				1973	return {"rectangle": $c}
				1974	</pre></div></div></li>
				1975	</ul>
				1976
				1977	<ul>
				1978
				1979	<li>
				1980	<p>The expected result is:</p>
				1981
				1982	<div class="source">
				1983	<div class="source">
				1984	<pre>{ "rectangle": rectangle("30.0,70.0 50.0,90.0") }
				1985	</pre></div></div></li>
				1986	</ul></div>
				1987	<div class="section">
				1988	<h3><a name="create-circle"></a>create-circle</h3>
				1989
				1990	<ul>
				1991
				1992	<li>
				1993	<p>Syntax:</p>
				1994
				1995	<div class="source">
				1996	<div class="source">
				1997	<pre>create-circle(point_expression, radius)
				1998	</pre></div></div></li>
				1999
				2000	<li>
				2001	<p>Creates the primitive type <tt>circle</tt> using <tt>point_expression</tt> and <tt>radius</tt>.</p></li>
				2002
				2003	<li>Arguments:
				2004
				2005	<ul>
				2006
				2007	<li><tt>point_expression</tt> : A <tt>point</tt> that represents the center of the circle.</li>
				2008
				2009	<li><tt>radius</tt> : A <tt>double</tt> that represents the radius of the circle.</li>
				2010	</ul></li>
				2011
				2012	<li>Return Value:
				2013
				2014	<ul>
				2015
				2016	<li>A spatial <tt>circle</tt> created using the center point and the radius provided in <tt>point_expression</tt> and <tt>radius</tt>.</li>
				2017	</ul></li>
				2018
				2019	<li>
				2020	<p>Example:</p>
				2021
				2022	<div class="source">
				2023	<div class="source">
				2024	<pre>use dataverse TinySocial;
				2025
				2026	let $c := create-circle(create-point(30.0,70.0), 5.0)
				2027	return {"circle": $c}
				2028	</pre></div></div></li>
				2029	</ul>
				2030
				2031	<ul>
				2032
				2033	<li>
				2034	<p>The expected result is:</p>
				2035
				2036	<div class="source">
				2037	<div class="source">
				2038	<pre>{ "circle": circle("30.0,70.0 5.0") }
				2039	</pre></div></div></li>
				2040	</ul></div>
				2041	<div class="section">
				2042	<h3><a name="create-polygon"></a>create-polygon</h3>
				2043
				2044	<ul>
				2045
				2046	<li>
				2047	<p>Syntax:</p>
				2048
				2049	<div class="source">
				2050	<div class="source">
				2051	<pre>create-polygon(list_expression)
				2052	</pre></div></div></li>
				2053
				2054	<li>
				2055	<p>Creates the primitive type <tt>polygon</tt> using the double values provided in the argument <tt>list_expression</tt>. Each two consecutive double values represent a point starting from the first double value in the list. Note that at least six double values should be specified, meaning a total of three points.</p></li>
				2056
				2057	<li>Arguments:</li>
				2058
				2059	<li><tt>list_expression</tt> : An OrderedList of doubles representing the points of the polygon.</li>
				2060
				2061	<li>Return Value:</li>
				2062
				2063	<li>A <tt>polygon</tt>, represents a spatial simple polygon created using the points provided in <tt>list_expression</tt>.</li>
				2064
				2065	<li>
				2066	<p>Example:</p>
				2067
				2068	<div class="source">
				2069	<div class="source">
				2070	<pre>use dataverse TinySocial;
				2071
				2072	let $c := create-polygon([1.0,1.0,2.0,2.0,3.0,3.0,4.0,4.0])
				2073	return {"polygon": $c}
				2074	</pre></div></div></li>
				2075	</ul>
				2076
				2077	<ul>
				2078
				2079	<li>
				2080	<p>The expected result is:</p>
				2081
				2082	<div class="source">
				2083	<div class="source">
				2084	<pre>{ "polygon": polygon("1.0,1.0 2.0,2.0 3.0,3.0 4.0,4.0") }
				2085	</pre></div></div></li>
				2086	</ul></div>
				2087	<div class="section">
				2088	<h3><a name="get-xget-y"></a>get-x/get-y</h3>
				2089
				2090	<ul>
				2091
				2092	<li>
				2093	<p>Syntax:</p>
				2094
				2095	<div class="source">
				2096	<div class="source">
				2097	<pre>get-x(point_expression) or get-y(point_expression)
				2098	</pre></div></div></li>
				2099
				2100	<li>
				2101	<p>Returns the x or y coordinates of a point <tt>point_expression</tt>.</p></li>
				2102
				2103	<li>Arguments:
				2104
				2105	<ul>
				2106
				2107	<li><tt>point_expression</tt> : A <tt>point</tt>.</li>
				2108	</ul></li>
				2109
				2110	<li>Return Value:
				2111
				2112	<ul>
				2113
				2114	<li>A <tt>double</tt> representing the x or y coordinates of the point <tt>point_expression</tt>.</li>
				2115	</ul></li>
				2116
				2117	<li>
				2118	<p>Example:</p>
				2119
				2120	<div class="source">
				2121	<div class="source">
				2122	<pre>use dataverse TinySocial;
				2123
				2124	let $point := create-point(2.3,5.0)
				2125	return {"x-coordinate": get-x($point), "y-coordinate": get-y($point)}
				2126	</pre></div></div></li>
				2127	</ul>
				2128
				2129	<ul>
				2130
				2131	<li>
				2132	<p>The expected result is:</p>
				2133
				2134	<div class="source">
				2135	<div class="source">
				2136	<pre>{ "x-coordinate": 2.3d, "y-coordinate": 5.0d }
				2137	</pre></div></div></li>
				2138	</ul></div>
				2139	<div class="section">
				2140	<h3><a name="get-points"></a>get-points</h3>
				2141
				2142	<ul>
				2143
				2144	<li>
				2145	<p>Syntax:</p>
				2146
				2147	<div class="source">
				2148	<div class="source">
				2149	<pre>get-points(spatial_expression)
				2150	</pre></div></div></li>
				2151
				2152	<li>
				2153	<p>Returns an ordered list of the points forming the spatial object <tt>spatial_expression</tt>.</p></li>
				2154
				2155	<li>Arguments:
				2156
				2157	<ul>
				2158
				2159	<li><tt>spatial_expression</tt> : A <tt>point</tt>, <tt>line</tt>, <tt>rectangle</tt>, <tt>circle</tt>, or <tt>polygon</tt>.</li>
				2160	</ul></li>
				2161
				2162	<li>Return Value:
				2163
				2164	<ul>
				2165
				2166	<li>An <tt>OrderedList</tt> of the points forming the spatial object <tt>spatial_expression</tt>.</li>
				2167	</ul></li>
				2168
				2169	<li>
				2170	<p>Example:</p>
				2171
				2172	<div class="source">
				2173	<div class="source">
				2174	<pre>use dataverse TinySocial;
				2175
				2176	let $line := create-line(create-point(100.6,99.4), create-point(-72.0,-76.9))
				2177	let $rectangle := create-rectangle(create-point(9.2,49.0), create-point(77.8,111.1))
				2178	let $polygon := create-polygon([1.0,1.0,2.0,2.0,3.0,3.0,4.0,4.0])
				2179	let $line_list := get-points($line)
				2180	let $rectangle_list := get-points($rectangle)
				2181	let $polygon_list := get-points($polygon)
				2182	return {"line-first-point": $line_list[0], "line-second-point": $line_list[1], "rectangle-left-bottom-point": $rectangle_list[0], "rectangle-top-upper-point": $rectangle_list[1], "polygon-first-point": $polygon_list[0], "polygon-second-point": $polygon_list[1], "polygon-third-point": $polygon_list[2], "polygon-forth-point": $polygon_list[3]}
				2183	</pre></div></div></li>
				2184	</ul>
				2185
				2186	<ul>
				2187
				2188	<li>
				2189	<p>The expected result is:</p>
				2190
				2191	<div class="source">
				2192	<div class="source">
				2193	<pre>{ "line-first-point": point("100.6,99.4"), "line-second-point": point("-72.0,-76.9"), "rectangle-left-bottom-point": point("9.2,49.0"), "rectangle-top-upper-point": point("77.8,111.1"), "polygon-first-point": point("1.0,1.0"), "polygon-second-point": point("2.0,2.0"), "polygon-third-point": point("3.0,3.0"), "polygon-forth-point": point("4.0,4.0") }
				2194	</pre></div></div></li>
				2195	</ul></div>
				2196	<div class="section">
				2197	<h3><a name="get-centerget-radius"></a>get-center/get-radius</h3>
				2198
				2199	<ul>
				2200
				2201	<li>
				2202	<p>Syntax:</p>
				2203
				2204	<div class="source">
				2205	<div class="source">
				2206	<pre>get-center(circle_expression) or get-radius(circle_expression)
				2207	</pre></div></div></li>
				2208
				2209	<li>
				2210	<p>Returns the center and the radius of a circle <tt>circle_expression</tt>, respectively.</p></li>
				2211
				2212	<li>Arguments:
				2213
				2214	<ul>
				2215
				2216	<li><tt>circle_expression</tt> : A <tt>circle</tt>.</li>
				2217	</ul></li>
				2218
				2219	<li>Return Value:
				2220
				2221	<ul>
				2222
				2223	<li>A <tt>point</tt> or <tt>double</tt>, represent the center or radius of the circle <tt>circle_expression</tt>.</li>
				2224	</ul></li>
				2225
				2226	<li>
				2227	<p>Example:</p>
				2228
				2229	<div class="source">
				2230	<div class="source">
				2231	<pre>use dataverse TinySocial;
				2232
				2233	let $circle := create-circle(create-point(6.0,3.0), 1.0)
				2234	return {"circle-radius": get-radius($circle), "circle-center": get-center($circle)}
				2235	</pre></div></div></li>
				2236	</ul>
				2237
				2238	<ul>
				2239
				2240	<li>
				2241	<p>The expected result is:</p>
				2242
				2243	<div class="source">
				2244	<div class="source">
				2245	<pre>{ "circle-radius": 1.0d, "circle-center": point("6.0,3.0") }
				2246	</pre></div></div></li>
				2247	</ul></div>
				2248	<div class="section">
				2249	<h3><a name="spatial-distance"></a>spatial-distance</h3>
				2250
				2251	<ul>
				2252
				2253	<li>
				2254	<p>Syntax:</p>
				2255
				2256	<div class="source">
				2257	<div class="source">
				2258	<pre>spatial-distance(point_expression1, point_expression2)
				2259	</pre></div></div></li>
				2260
				2261	<li>
				2262	<p>Returns the Euclidean distance between <tt>point_expression1</tt> and <tt>point_expression2</tt>.</p></li>
				2263
				2264	<li>Arguments:
				2265
				2266	<ul>
				2267
				2268	<li><tt>point_expression1</tt> : A <tt>point</tt>.</li>
				2269
				2270	<li><tt>point_expression2</tt> : A <tt>point</tt>.</li>
				2271	</ul></li>
				2272
				2273	<li>Return Value:
				2274
				2275	<ul>
				2276
				2277	<li>A <tt>double</tt> as the Euclidean distance between <tt>point_expression1</tt> and <tt>point_expression2</tt>.</li>
				2278	</ul></li>
				2279
				2280	<li>
				2281	<p>Example:</p>
				2282
				2283	<div class="source">
				2284	<div class="source">
				2285	<pre>use dataverse TinySocial;
				2286
				2287	for $t in dataset('TweetMessages')
				2288	let $d := spatial-distance($t.sender-location, create-point(30.0,70.0))
				2289	return {"point": $t.sender-location, "distance": $d}
				2290	</pre></div></div></li>
				2291	</ul>
				2292
				2293	<ul>
				2294
				2295	<li>
				2296	<p>The expected result is:</p>
				2297
				2298	<div class="source">
				2299	<div class="source">
				2300	<pre>{ "point": point("47.44,80.65"), "distance": 20.434678857275934d }
				2301	{ "point": point("29.15,76.53"), "distance": 6.585089217315132d }
				2302	{ "point": point("37.59,68.42"), "distance": 7.752709203884797d }
				2303	{ "point": point("24.82,94.63"), "distance": 25.168816023007512d }
				2304	{ "point": point("32.84,67.14"), "distance": 4.030533463451212d }
				2305	{ "point": point("29.72,75.8"), "distance": 5.806754687430835d }
				2306	{ "point": point("39.28,70.48"), "distance": 9.292405501268227d }
				2307	{ "point": point("40.09,92.69"), "distance": 24.832321679617472d }
				2308	{ "point": point("47.51,83.99"), "distance": 22.41250097601782d }
				2309	{ "point": point("36.21,72.6"), "distance": 6.73231758015024d }
				2310	{ "point": point("46.05,93.34"), "distance": 28.325926286707734d }
				2311	{ "point": point("36.86,74.62"), "distance": 8.270671073135482d }
				2312	</pre></div></div></li>
				2313	</ul></div>
				2314	<div class="section">
				2315	<h3><a name="spatial-area"></a>spatial-area</h3>
				2316
				2317	<ul>
				2318
				2319	<li>
				2320	<p>Syntax:</p>
				2321
				2322	<div class="source">
				2323	<div class="source">
				2324	<pre>spatial-area(spatial_2d_expression)
				2325	</pre></div></div></li>
				2326
				2327	<li>
				2328	<p>Returns the spatial area of <tt>spatial_2d_expression</tt>.</p></li>
				2329
				2330	<li>Arguments:
				2331
				2332	<ul>
				2333
				2334	<li><tt>spatial_2d_expression</tt> : A <tt>rectangle</tt>, <tt>circle</tt>, or <tt>polygon</tt>.</li>
				2335	</ul></li>
				2336
				2337	<li>Return Value:
				2338
				2339	<ul>
				2340
				2341	<li>A <tt>double</tt> representing the area of <tt>spatial_2d_expression</tt>.</li>
				2342	</ul></li>
				2343
				2344	<li>
				2345	<p>Example:</p>
				2346
				2347	<div class="source">
				2348	<div class="source">
				2349	<pre>use dataverse TinySocial;
				2350
				2351	let $circleArea := spatial-area(create-circle(create-point(0.0,0.0), 5.0))
				2352	return {"Area":$circleArea}
				2353	</pre></div></div></li>
				2354	</ul>
				2355
				2356	<ul>
				2357
				2358	<li>
				2359	<p>The expected result is:</p>
				2360
				2361	<div class="source">
				2362	<div class="source">
				2363	<pre>{ "Area": 78.53981625d }
				2364	</pre></div></div></li>
				2365	</ul></div>
				2366	<div class="section">
				2367	<h3><a name="spatial-intersect"></a>spatial-intersect</h3>
				2368
				2369	<ul>
				2370
				2371	<li>
				2372	<p>Syntax:</p>
				2373
				2374	<div class="source">
				2375	<div class="source">
				2376	<pre>spatial-intersect(spatial_expression1, spatial_expression2)
				2377	</pre></div></div></li>
				2378
				2379	<li>
				2380	<p>Checks whether <tt>@arg1</tt> and <tt>@arg2</tt> spatially intersect each other.</p></li>
				2381
				2382	<li>Arguments:
				2383
				2384	<ul>
				2385
				2386	<li><tt>spatial_expression1</tt> : A <tt>point</tt>, <tt>line</tt>, <tt>rectangle</tt>, <tt>circle</tt>, or <tt>polygon</tt>.</li>
				2387
				2388	<li><tt>spatial_expression2</tt> : A <tt>point</tt>, <tt>line</tt>, <tt>rectangle</tt>, <tt>circle</tt>, or <tt>polygon</tt>.</li>
				2389	</ul></li>
				2390
				2391	<li>Return Value:
				2392
				2393	<ul>
				2394
				2395	<li>A <tt>boolean</tt> representing whether <tt>spatial_expression1</tt> and <tt>spatial_expression2</tt> spatially overlap with each other.</li>
				2396	</ul></li>
				2397
				2398	<li>
				2399	<p>Example:</p>
				2400
				2401	<div class="source">
				2402	<div class="source">
				2403	<pre>use dataverse TinySocial;
				2404
				2405	for $t in dataset('TweetMessages')
				2406	where spatial-intersect($t.sender-location, create-rectangle(create-point(30.0,70.0), create-point(40.0,80.0)))
				2407	return $t
				2408	</pre></div></div></li>
				2409	</ul>
				2410
				2411	<ul>
				2412
				2413	<li>
				2414	<p>The expected result is:</p>
				2415
				2416	<div class="source">
				2417	<div class="source">
				2418	<pre>{ "tweetid": "4", "user": { "screen-name": "NathanGiesen@211", "lang": "en", "friends_count": 39339, "statuses_count": 473, "name": "Nathan Giesen", "followers_count": 49416 }, "sender-location": point("39.28,70.48"), "send-time": datetime("2011-12-26T10:10:00.000Z"), "referred-topics": {{ "sprint", "voice-command" }}, "message-text": " like sprint the voice-command is mind-blowing:)" }
				2419	{ "tweetid": "7", "user": { "screen-name": "ChangEwing_573", "lang": "en", "friends_count": 182, "statuses_count": 394, "name": "Chang Ewing", "followers_count": 32136 }, "sender-location": point("36.21,72.6"), "send-time": datetime("2011-08-25T10:10:00.000Z"), "referred-topics": {{ "samsung", "platform" }}, "message-text": " like samsung the platform is good" }
				2420	{ "tweetid": "9", "user": { "screen-name": "NathanGiesen@211", "lang": "en", "friends_count": 39339, "statuses_count": 473, "name": "Nathan Giesen", "followers_count": 49416 }, "sender-location": point("36.86,74.62"), "send-time": datetime("2012-07-21T10:10:00.000Z"), "referred-topics": {{ "verizon", "voicemail-service" }}, "message-text": " love verizon its voicemail-service is awesome" }
				2421	</pre></div></div></li>
				2422	</ul></div>
				2423	<div class="section">
				2424	<h3><a name="spatial-cell"></a>spatial-cell</h3>
				2425
				2426	<ul>
				2427
				2428	<li>
				2429	<p>Syntax:</p>
				2430
				2431	<div class="source">
				2432	<div class="source">
				2433	<pre>spatial-cell(point_expression1, point_expression2, x_increment, y_increment)
				2434	</pre></div></div></li>
				2435
				2436	<li>
				2437	<p>Returns the grid cell that <tt>point_expression1</tt> belongs to.</p></li>
				2438
				2439	<li>Arguments:
				2440
				2441	<ul>
				2442
				2443	<li><tt>point_expression1</tt> : A <tt>point</tt> representing the point of interest that its grid cell will be returned.</li>
				2444
				2445	<li><tt>point_expression2</tt> : A <tt>point</tt> representing the origin of the grid.</li>
				2446
				2447	<li><tt>x_increment</tt> : A <tt>double</tt>, represents X increments.</li>
				2448
				2449	<li><tt>y_increment</tt> : A <tt>double</tt>, represents Y increments.</li>
				2450	</ul></li>
				2451
				2452	<li>Return Value:
				2453
				2454	<ul>
				2455
				2456	<li>A <tt>rectangle</tt> representing the grid cell that <tt>point_expression1</tt> belongs to.</li>
				2457	</ul></li>
				2458
				2459	<li>
				2460	<p>Example:</p>
				2461
				2462	<div class="source">
				2463	<div class="source">
				2464	<pre>use dataverse TinySocial;
				2465
				2466	for $t in dataset('TweetMessages')
				2467	group by $c := spatial-cell($t.sender-location, create-point(20.0,50.0), 5.5, 6.0) with $t
				2468	let $num := count($t)
				2469	return { "cell": $c, "count": $num}
				2470	</pre></div></div></li>
				2471	</ul>
				2472
				2473	<ul>
				2474
				2475	<li>
				2476	<p>The expected result is:</p>
				2477
				2478	<div class="source">
				2479	<div class="source">
				2480	<pre>{ "cell": rectangle("20.0,92.0 25.5,98.0"), "count": 1i64 }
				2481	{ "cell": rectangle("25.5,74.0 31.0,80.0"), "count": 2i64 }
				2482	{ "cell": rectangle("31.0,62.0 36.5,68.0"), "count": 1i64 }
				2483	{ "cell": rectangle("31.0,68.0 36.5,74.0"), "count": 1i64 }
				2484	{ "cell": rectangle("36.5,68.0 42.0,74.0"), "count": 2i64 }
				2485	{ "cell": rectangle("36.5,74.0 42.0,80.0"), "count": 1i64 }
				2486	{ "cell": rectangle("36.5,92.0 42.0,98.0"), "count": 1i64 }
				2487	{ "cell": rectangle("42.0,80.0 47.5,86.0"), "count": 1i64 }
				2488	{ "cell": rectangle("42.0,92.0 47.5,98.0"), "count": 1i64 }
				2489	{ "cell": rectangle("47.5,80.0 53.0,86.0"), "count": 1i64 }
				2490	</pre></div></div></li>
				2491	</ul></div></div>
				2492	<div class="section">
				2493	<h2><a name="Similarity_Functions_Back_to_TOC"></a><a name="SimilarityFunctions" id="SimilarityFunctions">Similarity Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				2494	<p>AsterixDB supports queries with different similarity functions, including <a class="externalLink" href="http://en.wikipedia.org/wiki/Levenshtein_distance">edit distance</a> and <a class="externalLink" href="https://en.wikipedia.org/wiki/Jaccard_index">Jaccard</a>.</p>
				2495	<div class="section">
				2496	<h3><a name="edit-distance"></a>edit-distance</h3>
				2497
				2498	<ul>
				2499
				2500	<li>
				2501	<p>Syntax:</p>
				2502
				2503	<div class="source">
				2504	<div class="source">
				2505	<pre>edit-distance(expression1, expression2)
				2506	</pre></div></div></li>
				2507
				2508	<li>
				2509	<p>Returns the edit distance of <tt>expression1</tt> and <tt>expression2</tt>.</p></li>
				2510
				2511	<li>Arguments:
				2512
				2513	<ul>
				2514
				2515	<li><tt>expression1</tt> : A <tt>string</tt> or a homogeneous <tt>OrderedList</tt> of a comparable item type.</li>
				2516
				2517	<li><tt>expression2</tt> : The same type as <tt>expression1</tt>.</li>
				2518	</ul></li>
				2519
				2520	<li>Return Value:
				2521
				2522	<ul>
				2523
				2524	<li>An <tt>int64</tt> that represents the edit distance between <tt>expression1</tt> and <tt>expression2</tt>.</li>
				2525	</ul></li>
				2526
				2527	<li>Note: An <a href="similarity.html#UsingIndexesToSupportSimilarityQueries">n-gram index</a> can be utilized for this function.</li>
				2528
				2529	<li>
				2530	<p>Example:</p>
				2531
				2532	<div class="source">
				2533	<div class="source">
				2534	<pre>use dataverse TinySocial;
				2535
				2536	for $user in dataset('FacebookUsers')
				2537	let $ed := edit-distance($user.name, "Suzanna Tilson")
				2538	where $ed <= 2
				2539	return $user
				2540	</pre></div></div></li>
				2541	</ul>
				2542
				2543	<ul>
				2544
				2545	<li>
				2546	<p>The expected result is:</p>
				2547
				2548	<div class="source">
				2549	<div class="source">
				2550	<pre>{
				2551	"id": 7, "alias": "Suzanna", "name": "SuzannaTillson", "user-since": datetime("2012-08-07T10:10:00.000Z"), "friend-ids": {{ 6 }},
				2552	"employment": [ { "organization-name": "Labzatron", "start-date": date("2011-04-19"), "end-date": null } ]
				2553	}
				2554	</pre></div></div></li>
				2555	</ul></div>
				2556	<div class="section">
				2557	<h3><a name="edit-distance-check"></a>edit-distance-check</h3>
				2558
				2559	<ul>
				2560
				2561	<li>
				2562	<p>Syntax:</p>
				2563
				2564	<div class="source">
				2565	<div class="source">
				2566	<pre>edit-distance-check(expression1, expression2, threshold)
				2567	</pre></div></div></li>
				2568
				2569	<li>
				2570	<p>Checks whether <tt>expression1</tt> and <tt>expression2</tt> have an <a class="externalLink" href="http://en.wikipedia.org/wiki/Levenshtein_distance">edit distance</a> within a given threshold. The “check” version of edit distance is faster than the “non-check” version because the former can detect whether two items satisfy a given threshold using early-termination techniques, as opposed to computing their real distance. Although possible, it is not necessary for the user to write queries using the “check” versions explicitly, since a rewrite rule can perform an appropriate transformation from a “non-check” version to a “check” version.</p></li>
				2571
				2572	<li>
				2573	<p>Arguments:</p>
				2574
				2575	<ul>
				2576
				2577	<li><tt>expression1</tt> : A <tt>string</tt> or a homogeneous <tt>OrderedList</tt> of a comparable item type.</li>
				2578
				2579	<li><tt>expression2</tt> : The same type as <tt>expression1</tt>.</li>
				2580
				2581	<li><tt>threshold</tt> : An <tt>int64</tt> that represents the distance threshold.</li>
				2582	</ul></li>
				2583
				2584	<li>Return Value:
				2585
				2586	<ul>
				2587
				2588	<li>An <tt>OrderedList</tt> with two items:
				2589
				2590	<ul>
				2591
				2592	<li>The first item contains a <tt>boolean</tt> value representing whether <tt>expression1</tt> and <tt>expression2</tt> are similar.</li>
				2593
				2594	<li>The second item contains an <tt>int64</tt> that represents the edit distance of <tt>expression1</tt> and <tt>expression2</tt> if it is within the threshold, or 0 otherwise.</li>
				2595	</ul></li>
				2596	</ul></li>
				2597
				2598	<li>Note: An <a href="similarity.html#UsingIndexesToSupportSimilarityQueries">n-gram index</a> can be utilized for this function.</li>
				2599
				2600	<li>
				2601	<p>Example:</p>
				2602
				2603	<div class="source">
				2604	<div class="source">
				2605	<pre>use dataverse TinySocial;
				2606
				2607	for $user in dataset('FacebookUsers')
				2608	let $ed := edit-distance-check($user.name, "Suzanna Tilson", 2)
				2609	where $ed[0]
				2610	return $ed[1]
				2611	</pre></div></div></li>
				2612	</ul>
				2613
				2614	<ul>
				2615
				2616	<li>
				2617	<p>The expected result is:</p>
				2618
				2619	<div class="source">
				2620	<div class="source">
				2621	<pre>2
				2622	</pre></div></div></li>
				2623	</ul></div>
				2624	<div class="section">
				2625	<h3><a name="edit-distance-contains"></a>edit-distance-contains</h3>
				2626
				2627	<ul>
				2628
				2629	<li>Syntax:</li>
				2630	</ul>
				2631	<p>edit-distance-contains(expression1, expression2, threshold)</p>
				2632
				2633	<ul>
				2634
				2635	<li>
				2636	<p>Checks whether <tt>expression1</tt> contains <tt>expression2</tt> with an <a class="externalLink" href="http://en.wikipedia.org/wiki/Levenshtein_distance">edit distance</a> within a given threshold.</p></li>
				2637
				2638	<li>
				2639	<p>Arguments:</p>
				2640
				2641	<ul>
				2642
				2643	<li><tt>expression1</tt> : A <tt>string</tt> or a homogeneous <tt>OrderedList</tt> of a comparable item type.</li>
				2644
				2645	<li><tt>expression2</tt> : The same type as <tt>expression1</tt>.</li>
				2646
				2647	<li><tt>threshold</tt> : An <tt>int32</tt> that represents the distance threshold.</li>
				2648	</ul></li>
				2649
				2650	<li>Return Value:
				2651
				2652	<ul>
				2653
				2654	<li>An <tt>OrderedList</tt> with two items:
				2655
				2656	<ul>
				2657
				2658	<li>The first item contains a <tt>boolean</tt> value representing whether <tt>expression1</tt> can contain <tt>expression2</tt>.</li>
				2659
				2660	<li>The second item contains an <tt>int32</tt> that represents the required edit distance for <tt>expression1</tt> to contain <tt>expression2</tt> if the first item is true.</li>
				2661	</ul></li>
				2662	</ul></li>
				2663
				2664	<li>Note: An <a href="similarity.html#UsingIndexesToSupportSimilarityQueries">n-gram index</a> can be utilized for this function.</li>
				2665
				2666	<li>
				2667	<p>Example:</p>
				2668
				2669	<div class="source">
				2670	<div class="source">
				2671	<pre>let $i := edit-distance-contains("happy","hapr",2)
				2672	return $i;
				2673	</pre></div></div></li>
				2674	</ul>
				2675
				2676	<ul>
				2677
				2678	<li>
				2679	<p>The expected result is:</p>
				2680
				2681	<div class="source">
				2682	<div class="source">
				2683	<pre>[ true, 1 ]
				2684	</pre></div></div></li>
				2685	</ul></div>
				2686	<div class="section">
				2687	<h3><a name="similarity-jaccard"></a>similarity-jaccard</h3>
				2688
				2689	<ul>
				2690
				2691	<li>
				2692	<p>Syntax:</p>
				2693
				2694	<div class="source">
				2695	<div class="source">
				2696	<pre>similarity-jaccard(list_expression1, list_expression2)
				2697	</pre></div></div></li>
				2698
				2699	<li>
				2700	<p>Returns the <a class="externalLink" href="http://en.wikipedia.org/wiki/Jaccard_index">Jaccard similarity</a> of <tt>list_expression1</tt> and <tt>list_expression2</tt>.</p></li>
				2701
				2702	<li>Arguments:
				2703
				2704	<ul>
				2705
				2706	<li><tt>list_expression1</tt> : An <tt>UnorderedList</tt> or <tt>OrderedList</tt>.</li>
				2707
				2708	<li><tt>list_expression2</tt> : An <tt>UnorderedList</tt> or <tt>OrderedList</tt>.</li>
				2709	</ul></li>
				2710
				2711	<li>Return Value:
				2712
				2713	<ul>
				2714
				2715	<li>A <tt>float</tt> that represents the Jaccard similarity of <tt>list_expression1</tt> and <tt>list_expression2</tt>.</li>
				2716	</ul></li>
				2717
				2718	<li>Note: A <a href="similarity.html#UsingIndexesToSupportSimilarityQueries">keyword index</a> can be utilized for this function.</li>
				2719
				2720	<li>
				2721	<p>Example:</p>
				2722
				2723	<div class="source">
				2724	<div class="source">
				2725	<pre>use dataverse TinySocial;
				2726
				2727	for $user in dataset('FacebookUsers')
				2728	let $sim := similarity-jaccard($user.friend-ids, [1,5,9,10])
				2729	where $sim >= 0.6f
				2730	return $user
				2731	</pre></div></div></li>
				2732	</ul>
				2733
				2734	<ul>
				2735
				2736	<li>
				2737	<p>The expected result is:</p>
				2738
				2739	<div class="source">
				2740	<div class="source">
				2741	<pre>{
				2742	"id": 3, "alias": "Emory", "name": "EmoryUnk", "user-since": datetime("2012-07-10T10:10:00.000Z"), "friend-ids": {{ 1, 5, 8, 9 }},
				2743	"employment": [ { "organization-name": "geomedia", "start-date": date("2010-06-17"), "end-date": date("2010-01-26") } ]
				2744	}
				2745	{
				2746	"id": 10, "alias": "Bram", "name": "BramHatch", "user-since": datetime("2010-10-16T10:10:00.000Z"), "friend-ids": {{ 1, 5, 9 }},
				2747	"employment": [ { "organization-name": "physcane", "start-date": date("2007-06-05"), "end-date": date("2011-11-05") } ]
				2748	}
				2749	</pre></div></div></li>
				2750	</ul></div>
				2751	<div class="section">
				2752	<h3><a name="similarity-jaccard-check"></a>similarity-jaccard-check</h3>
				2753
				2754	<ul>
				2755
				2756	<li>
				2757	<p>Syntax:</p>
				2758
				2759	<div class="source">
				2760	<div class="source">
				2761	<pre>similarity-jaccard-check(list_expression1, list_expression2, threshold)
				2762	</pre></div></div></li>
				2763
				2764	<li>
				2765	<p>Checks whether <tt>list_expression1</tt> and <tt>list_expression2</tt> have a <a class="externalLink" href="http://en.wikipedia.org/wiki/Jaccard_index">Jaccard similarity</a> greater than or equal to threshold. Again, the “check” version of Jaccard is faster than the “non-check” version.</p></li>
				2766
				2767	<li>
				2768	<p>Arguments:</p>
				2769
				2770	<ul>
				2771
				2772	<li><tt>list_expression1</tt> : An <tt>UnorderedList</tt> or <tt>OrderedList</tt>.</li>
				2773
				2774	<li><tt>list_expression2</tt> : An <tt>UnorderedList</tt> or <tt>OrderedList</tt>.</li>
				2775
				2776	<li><tt>threshold</tt> : A <tt>float</tt> that represents the similarity threshold.</li>
				2777	</ul></li>
				2778
				2779	<li>Return Value:
				2780
				2781	<ul>
				2782
				2783	<li>An <tt>OrderedList</tt> with two items:</li>
				2784
				2785	<li>The first item contains a <tt>boolean</tt> value representing whether <tt>list_expression1</tt> and <tt>list_expression2</tt> are similar.</li>
				2786
				2787	<li>The second item contains a <tt>float</tt> that represents the Jaccard similarity of <tt>list_expression1</tt> and <tt>list_expression2</tt> if it is greater than or equal to the threshold, or 0 otherwise.</li>
				2788	</ul></li>
				2789
				2790	<li>Note: A <a href="similarity.html#UsingIndexesToSupportSimilarityQueries">keyword index</a> can be utilized for this function.</li>
				2791
				2792	<li>
				2793	<p>Example:</p>
				2794
				2795	<div class="source">
				2796	<div class="source">
				2797	<pre>use dataverse TinySocial;
				2798
				2799	for $user in dataset('FacebookUsers')
				2800	let $sim := similarity-jaccard-check($user.friend-ids, [1,5,9,10], 0.6f)
				2801	where $sim[0]
				2802	return $sim[1]
				2803	</pre></div></div></li>
				2804	</ul>
				2805
				2806	<ul>
				2807
				2808	<li>
				2809	<p>The expected result is:</p>
				2810
				2811	<div class="source">
				2812	<div class="source">
				2813	<pre>0.75f
				2814	1.0f
				2815	</pre></div></div></li>
				2816	</ul></div>
				2817	<div class="section">
				2818	<h3><a name="Similarity_Operator_"></a>Similarity Operator ~=</h3>
				2819
				2820	<ul>
				2821
				2822	<li>“<tt>~=</tt>” is syntactic sugar for expressing a similarity condition with a given similarity threshold.</li>
				2823
				2824	<li>The similarity function and threshold for “<tt>~=</tt>” are controlled via “set” directives.</li>
				2825
				2826	<li>The “<tt>~=</tt>” operator returns a <tt>boolean</tt> value that represents whether the operands are similar.</li>
				2827
				2828	<li>
				2829	<p>Example for Jaccard similarity:</p>
				2830
				2831	<div class="source">
				2832	<div class="source">
				2833	<pre>use dataverse TinySocial;
				2834
				2835	set simfunction "jaccard";
				2836	set simthreshold "0.6f";
				2837
				2838	for $user in dataset('FacebookUsers')
				2839	where $user.friend-ids ~= [1,5,9,10]
				2840	return $user
				2841	</pre></div></div></li>
				2842	</ul>
				2843
				2844	<ul>
				2845
				2846	<li>
				2847	<p>The expected result is:</p>
				2848
				2849	<div class="source">
				2850	<div class="source">
				2851	<pre>{
				2852	"id": 3, "alias": "Emory", "name": "EmoryUnk", "user-since": datetime("2012-07-10T10:10:00.000Z"), "friend-ids": {{ 1, 5, 8, 9 }},
				2853	"employment": [ { "organization-name": "geomedia", "start-date": date("2010-06-17"), "end-date": date("2010-01-26") } ]
				2854	}
				2855	{
				2856	"id": 10, "alias": "Bram", "name": "BramHatch", "user-since": datetime("2010-10-16T10:10:00.000Z"), "friend-ids": {{ 1, 5, 9 }},
				2857	"employment": [ { "organization-name": "physcane", "start-date": date("2007-06-05"), "end-date": date("2011-11-05") } ]
				2858	}
				2859	</pre></div></div></li>
				2860	</ul>
				2861
				2862	<ul>
				2863
				2864	<li>
				2865	<p>Example for edit-distance similarity:</p>
				2866
				2867	<div class="source">
				2868	<div class="source">
				2869	<pre>use dataverse TinySocial;
				2870
				2871	set simfunction "edit-distance";
				2872	set simthreshold "2";
				2873
				2874	for $user in dataset('FacebookUsers')
				2875	where $user.name ~= "Suzanna Tilson"
				2876	return $user
				2877	</pre></div></div></li>
				2878	</ul>
				2879
				2880	<ul>
				2881
				2882	<li>
				2883	<p>The expected output is:</p>
				2884
				2885	<div class="source">
				2886	<div class="source">
				2887	<pre>{
				2888	"id": 7, "alias": "Suzanna", "name": "SuzannaTillson", "user-since": datetime("2012-08-07T10:10:00.000Z"), "friend-ids": {{ 6 }},
				2889	"employment": [ { "organization-name": "Labzatron", "start-date": date("2011-04-19"), "end-date": null } ]
				2890	}
				2891	</pre></div></div></li>
				2892	</ul></div></div>
				2893	<div class="section">
				2894	<h2><a name="Tokenizing_Functions_Back_to_TOC"></a><a name="TokenizingFunctions" id="TokenizingFunctions">Tokenizing Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				2895	<div class="section">
				2896	<h3><a name="word-tokens"></a>word-tokens</h3>
				2897
				2898	<ul>
				2899
				2900	<li>
				2901	<p>Syntax:</p>
				2902
				2903	<div class="source">
				2904	<div class="source">
				2905	<pre>word-tokens(string_expression)
				2906	</pre></div></div></li>
				2907
				2908	<li>
				2909	<p>Returns a list of word tokens of <tt>string_expression</tt> using non-alphanumeric characters as delimiters.</p></li>
				2910
				2911	<li>Arguments:
				2912
				2913	<ul>
				2914
				2915	<li><tt>string_expression</tt> : A <tt>string</tt> that will be tokenized.</li>
				2916	</ul></li>
				2917
				2918	<li>Return Value:
				2919
				2920	<ul>
				2921
				2922	<li>An <tt>OrderedList</tt> of <tt>string</tt> word tokens.</li>
				2923	</ul></li>
				2924
				2925	<li>
				2926	<p>Example:</p>
				2927
				2928	<div class="source">
				2929	<div class="source">
				2930	<pre>use dataverse TinySocial;
				2931
				2932	for $t in dataset('TweetMessages')
				2933	let $tokens := word-tokens($t.message-text)
				2934	where $t.send-time >= datetime('2012-01-01T00:00:00')
				2935	return {
				2936	"tweetid": $t.tweetid,
				2937	"word-tokens": $tokens
				2938	}
				2939	</pre></div></div></li>
				2940	</ul>
				2941
				2942	<ul>
				2943
				2944	<li>
				2945	<p>The expected result is:</p>
				2946
				2947	<div class="source">
				2948	<div class="source">
				2949	<pre>{ "tweetid": "9", "word-tokens": [ "love", "verizon", "its", "voicemail", "service", "is", "awesome" ] }
				2950	</pre></div></div></li>
				2951	</ul>
				2952	<!-- ### hashed-word-tokens ###
				2953	* Syntax:
				2954
				2955	hashed-word-tokens(string_expression)
				2956
				2957	* Returns a list of hashed word tokens of `string_expression`.
				2958	* Arguments:
				2959	* `string_expression` : A `string` that will be tokenized.
				2960	* Return Value:
				2961	* An `OrderedList` of `int32` hashed tokens.
				2962
				2963	* Example:
				2964
				2965	use dataverse TinySocial;
				2966
				2967	for $t in dataset('TweetMessages')
				2968	let $tokens := hashed-word-tokens($t.message-text)
				2969	where $t.send-time >= datetime('2012-01-01T00:00:00')
				2970	return {
				2971	"tweetid": $t.tweetid,
				2972	"hashed-word-tokens": $tokens
				2973	}
				2974
				2975
				2976	* The expected result is:
				2977
				2978	{ "tweetid": "9", "hashed-word-tokens": [ -1217719622, -447857469, -1884722688, -325178649, 210976949, 285049676, 1916743959 ] }
				2979
				2980
				2981	### counthashed-word-tokens ###
				2982	* Syntax:
				2983
				2984	counthashed-word-tokens(string_expression)
				2985
				2986	* Returns a list of hashed word tokens of `string_expression`. The hashing mechanism gives duplicate tokens different hash values, based on the occurrence count of that token.
				2987	* Arguments:
				2988	* `string_expression` : A `String` that will be tokenized.
				2989	* Return Value:
				2990	* An `OrderedList` of `Int32` hashed tokens.
				2991	* Example:
				2992
				2993	use dataverse TinySocial;
				2994
				2995	for $t in dataset('TweetMessages')
				2996	let $tokens := counthashed-word-tokens($t.message-text)
				2997	where $t.send-time >= datetime('2012-01-01T00:00:00')
				2998	return {
				2999	"tweetid": $t.tweetid,
				3000	"counthashed-word-tokens": $tokens
				3001	}
				3002
				3003
				3004	* The expected result is:
				3005
				3006	{ "tweetid": "9", "counthashed-word-tokens": [ -1217719622, -447857469, -1884722688, -325178649, 210976949, 285049676, 1916743959 ] }
				3007
				3008
				3009	### gram-tokens ###
				3010	* Syntax:
				3011
				3012	gram-tokens(string_expression, gram_length, boolean_expression)
				3013
				3014	* Returns a list of gram tokens of `string_expression`, which can be obtained by scanning the characters using a sliding window of a fixed length.
				3015	* Arguments:
				3016	* `string_expression` : A `String` that will be tokenized.
				3017	* `gram_length` : An `Int32` as the length of grams.
				3018	* `boolean_expression` : A `Boolean` value to indicate whether to generate additional grams by pre- and postfixing `string_expression` with special characters.
				3019	* Return Value:
				3020	* An `OrderedList` of String gram tokens.
				3021
				3022	* Example:
				3023
				3024	use dataverse TinySocial;
				3025
				3026	for $t in dataset('TweetMessages')
				3027	let $tokens := gram-tokens($t.message-text, 3, true)
				3028	where $t.send-time >= datetime('2012-01-01T00:00:00')
				3029	return {
				3030	"tweetid": $t.tweetid,
				3031	"gram-tokens": $tokens
				3032	}
				3033
				3034
				3035	* The expected result is:
				3036
				3037	{
				3038	"tweetid": "9",
				3039	"gram-tokens": [ "## ", "# l", " lo", "lov", "ove", "ve ", "e v", " ve", "ver", "eri", "riz", "izo", "zon", "on ", "n i", " it", "its", "ts ", "s v", " vo", "voi", "oic", "ice",
				3040	"cem", "ema", "mai", "ail", "il-", "l-s", "-se", "ser", "erv", "rvi", "vic", "ice", "ce ", "e i", " is", "is ", "s a", " aw", "awe", "wes", "eso", "som", "ome", "me$", "e$$" ]
				3041	}
				3042
				3043
				3044	### hashed-gram-tokens ###
				3045	* Syntax:
				3046
				3047	hashed-gram-tokens(string_expression, gram_length, boolean_expression)
				3048
				3049	* Returns a list of hashed gram tokens of `string_expression`.
				3050	* Arguments:
				3051	* `string_expression` : A `String` that will be tokenized.
				3052	* `gram_length` : An `Int32` as the length of grams.
				3053	* `boolean_expression` : A `Boolean` to indicate whether to generate additional grams by pre- and postfixing `string_expression` with special characters.
				3054	* Return Value:
				3055	* An `OrderedList` of `Int32` hashed gram tokens.
				3056
				3057	* Example:
				3058
				3059	use dataverse TinySocial;
				3060
				3061	for $t in dataset('TweetMessages')
				3062	let $tokens := hashed-gram-tokens($t.message-text, 3, true)
				3063	where $t.send-time >= datetime('2012-01-01T00:00:00')
				3064	return {
				3065	"tweetid": $t.tweetid,
				3066	"hashed-gram-tokens": $tokens
				3067	}
				3068
				3069
				3070	* The expected result is:
				3071
				3072	{
				3073	"tweetid": "9",
				3074	"hashed-gram-tokens": [ 40557178, -2002241593, 161665899, -856104603, -500544946, 693410611, 395674299, -1015235909, 1115608337, 1187999872, -31006095, -219180466, -1676061637,
				3075	1040194153, -1339307841, -1527110163, -1884722688, -179148713, -431014627, -1789789823, -1209719926, 684519765, -486734513, 1734740619, -1971673751, -932421915, -2064668066,
				3076	-937135958, -790946468, -69070309, 1561601454, 26169001, -160734571, 1330043462, -486734513, -18796768, -470303314, 113421364, 1615760212, 1688217556, 1223719184, 536568131,
				3077	1682609873, 2935161, -414769471, -1027490137, 1602276102, 1050490461 ]
				3078	}
				3079
				3080
				3081	### counthashed-gram-tokens ###
				3082	* Syntax:
				3083
				3084	counthashed-gram-tokens(string_expression, gram_length, boolean_expression)
				3085
				3086	* Returns a list of hashed gram tokens of `string_expression`. The hashing mechanism gives duplicate tokens different hash values, based on the occurrence count of that token.
				3087	* Arguments:
				3088	* `string_expression` : A `String` that will be tokenized.
				3089	* `gram_length` : An `Int32`, length of grams to generate.
				3090	* `boolean_expression` : A `Boolean`, whether to generate additional grams by pre- and postfixing `string_expression` with special characters.
				3091	* Return Value:
				3092	* An `OrderedList` of `Int32` hashed gram tokens.
				3093
				3094	* Example:
				3095
				3096	use dataverse TinySocial;
				3097
				3098	for $t in dataset('TweetMessages')
				3099	let $tokens := counthashed-gram-tokens($t.message-text, 3, true)
				3100	where $t.send-time >= datetime('2012-01-01T00:00:00')
				3101	return {
				3102	"tweetid": $t.tweetid,
				3103	"counthashed-gram-tokens": $tokens
				3104	}
				3105
				3106
				3107	* The expected result is:
				3108
				3109	{
				3110	"tweetid": "9",
				3111	"counthashed-gram-tokens": [ 40557178, -2002241593, 161665899, -856104603, -500544946, 693410611, 395674299, -1015235909, 1115608337, 1187999872, -31006095, -219180466, -1676061637,
				3112	1040194153, -1339307841, -1527110163, -1884722688, -179148713, -431014627, -1789789823, -1209719926, 684519765, -486734513, 1734740619, -1971673751, -932421915, -2064668066, -937135958,
				3113	-790946468, -69070309, 1561601454, 26169001, -160734571, 1330043462, -486734512, -18796768, -470303314, 113421364, 1615760212, 1688217556, 1223719184, 536568131, 1682609873, 2935161,
				3114	-414769471, -1027490137, 1602276102, 1050490461 ]
				3115	} --></div></div>
				3116	<div class="section">
				3117	<h2><a name="Temporal_Functions_Back_to_TOC"></a><a name="TemporalFunctions" id="TemporalFunctions">Temporal Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				3118	<div class="section">
				3119	<h3><a name="get-yearget-monthget-dayget-hourget-minuteget-secondget-millisecond"></a>get-year/get-month/get-day/get-hour/get-minute/get-second/get-millisecond</h3>
				3120
				3121	<ul>
				3122
				3123	<li>
				3124	<p>Syntax:</p>
				3125
				3126	<div class="source">
				3127	<div class="source">
				3128	<pre>get-year/get-month/get-day/get-hour/get-minute/get-second/get-millisecond(temporal_expression)
				3129	</pre></div></div></li>
				3130
				3131	<li>
				3132	<p>Accessors for accessing fields in a temporal value</p></li>
				3133
				3134	<li>Arguments:
				3135
				3136	<ul>
				3137
				3138	<li><tt>temporal_expression</tt> : a temporal value represented as one of the following types: <tt>date</tt>, <tt>datetime</tt>, <tt>time</tt>, and <tt>duration</tt>.</li>
				3139	</ul></li>
				3140
				3141	<li>Return Value:
				3142
				3143	<ul>
				3144
				3145	<li>An <tt>int64</tt> value representing the field to be extracted.</li>
				3146	</ul></li>
				3147
				3148	<li>
				3149	<p>Example:</p>
				3150
				3151	<div class="source">
				3152	<div class="source">
				3153	<pre>let $c1 := date("2010-10-30")
				3154	let $c2 := datetime("1987-11-19T23:49:23.938")
				3155	let $c3 := time("12:23:34.930+07:00")
				3156	let $c4 := duration("P3Y73M632DT49H743M3948.94S")
				3157
				3158	return {"year": get-year($c1), "month": get-month($c2), "day": get-day($c1), "hour": get-hour($c3), "min": get-minute($c4), "second": get-second($c2), "ms": get-millisecond($c4)}
				3159	</pre></div></div></li>
				3160	</ul>
				3161
				3162	<ul>
				3163
				3164	<li>
				3165	<p>The expected result is:</p>
				3166
				3167	<div class="source">
				3168	<div class="source">
				3169	<pre>{ "year": 2010, "month": 11, "day": 30, "hour": 5, "min": 28, "second": 23, "ms": 94 }
				3170	</pre></div></div></li>
				3171	</ul></div>
				3172	<div class="section">
				3173	<h3><a name="adjust-datetime-for-timezone"></a>adjust-datetime-for-timezone</h3>
				3174
				3175	<ul>
				3176
				3177	<li>
				3178	<p>Syntax:</p>
				3179
				3180	<div class="source">
				3181	<div class="source">
				3182	<pre>adjust-datetime-for-timezone(datetime_expression, string_expression)
				3183	</pre></div></div></li>
				3184
				3185	<li>
				3186	<p>Adjusts the given datetime <tt>datetime_expression</tt> by applying the timezone information <tt>string_expression</tt>.</p></li>
				3187
				3188	<li>Arguments:
				3189
				3190	<ul>
				3191
				3192	<li><tt>datetime_expression</tt> : A <tt>datetime</tt> value to be adjusted.</li>
				3193
				3194	<li><tt>string_expression</tt> : A <tt>string</tt> representing the timezone information.</li>
				3195	</ul></li>
				3196
				3197	<li>Return Value:
				3198
				3199	<ul>
				3200
				3201	<li>A <tt>string</tt> value representing the new datetime after being adjusted by the timezone information.</li>
				3202	</ul></li>
				3203
				3204	<li>
				3205	<p>Example:</p>
				3206
				3207	<div class="source">
				3208	<div class="source">
				3209	<pre>use dataverse TinySocial;
				3210
				3211	for $i in dataset('TweetMessages')
				3212	return {"adjusted-send-time": adjust-datetime-for-timezone($i.send-time, "+08:00"), "message": $i.message-text}
				3213	</pre></div></div></li>
				3214	</ul>
				3215
				3216	<ul>
				3217
				3218	<li>
				3219	<p>The expected result is:</p>
				3220
				3221	<div class="source">
				3222	<div class="source">
				3223	<pre>{ "adjusted-send-time": "2008-04-26T18:10:00.000+08:00", "message": " love t-mobile its customization is good:)" }
				3224	{ "adjusted-send-time": "2010-05-13T18:10:00.000+08:00", "message": " like verizon its shortcut-menu is awesome:)" }
				3225	{ "adjusted-send-time": "2006-11-04T18:10:00.000+08:00", "message": " like motorola the speed is good:)" }
				3226	{ "adjusted-send-time": "2011-12-26T18:10:00.000+08:00", "message": " like sprint the voice-command is mind-blowing:)" }
				3227	{ "adjusted-send-time": "2006-08-04T18:10:00.000+08:00", "message": " can't stand motorola its speed is terrible:(" }
				3228	{ "adjusted-send-time": "2010-05-07T18:10:00.000+08:00", "message": " like iphone the voice-clarity is good:)" }
				3229	{ "adjusted-send-time": "2011-08-25T18:10:00.000+08:00", "message": " like samsung the platform is good" }
				3230	{ "adjusted-send-time": "2005-10-14T18:10:00.000+08:00", "message": " like t-mobile the shortcut-menu is awesome:)" }
				3231	{ "adjusted-send-time": "2012-07-21T18:10:00.000+08:00", "message": " love verizon its voicemail-service is awesome" }
				3232	{ "adjusted-send-time": "2008-01-26T18:10:00.000+08:00", "message": " hate verizon its voice-clarity is OMG:(" }
				3233	{ "adjusted-send-time": "2008-03-09T18:10:00.000+08:00", "message": " can't stand iphone its platform is terrible" }
				3234	{ "adjusted-send-time": "2010-02-13T18:10:00.000+08:00", "message": " like samsung the voice-command is amazing:)" }
				3235	</pre></div></div></li>
				3236	</ul></div>
				3237	<div class="section">
				3238	<h3><a name="adjust-time-for-timezone"></a>adjust-time-for-timezone</h3>
				3239
				3240	<ul>
				3241
				3242	<li>
				3243	<p>Syntax:</p>
				3244
				3245	<div class="source">
				3246	<div class="source">
				3247	<pre>adjust-time-for-timezone(time_expression, string_expression)
				3248	</pre></div></div></li>
				3249
				3250	<li>
				3251	<p>Adjusts the given time <tt>time_expression</tt> by applying the timezone information <tt>string_expression</tt>.</p></li>
				3252
				3253	<li>Arguments:
				3254
				3255	<ul>
				3256
				3257	<li><tt>time_expression</tt> : A <tt>time</tt> value to be adjusted.</li>
				3258
				3259	<li><tt>string_expression</tt> : A <tt>string</tt> representing the timezone information.</li>
				3260	</ul></li>
				3261
				3262	<li>Return Value:
				3263
				3264	<ul>
				3265
				3266	<li>A <tt>string</tt> value representing the new time after being adjusted by the timezone information.</li>
				3267	</ul></li>
				3268
				3269	<li>
				3270	<p>Example:</p>
				3271
				3272	<div class="source">
				3273	<div class="source">
				3274	<pre>use dataverse TinySocial;
				3275
				3276	for $i in dataset('TweetMessages')
				3277	return {"adjusted-send-time": adjust-time-for-timezone(time-from-datetime($i.send-time), "+08:00"), "message": $i.message-text}
				3278	</pre></div></div></li>
				3279	</ul>
				3280
				3281	<ul>
				3282
				3283	<li>
				3284	<p>The expected result is:</p>
				3285
				3286	<div class="source">
				3287	<div class="source">
				3288	<pre>{ "adjusted-send-time": "18:10:00.000+08:00", "message": " love t-mobile its customization is good:)" }
				3289	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " like verizon its shortcut-menu is awesome:)" }
				3290	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " like motorola the speed is good:)" }
				3291	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " like sprint the voice-command is mind-blowing:)" }
				3292	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " can't stand motorola its speed is terrible:(" }
				3293	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " like iphone the voice-clarity is good:)" }
				3294	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " like samsung the platform is good" }
				3295	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " like t-mobile the shortcut-menu is awesome:)" }
				3296	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " love verizon its voicemail-service is awesome" }
				3297	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " hate verizon its voice-clarity is OMG:(" }
				3298	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " can't stand iphone its platform is terrible" }
				3299	{ "adjusted-send-time": "18:10:00.000+08:00", "message": " like samsung the voice-command is amazing:)" }
				3300	</pre></div></div></li>
				3301	</ul></div>
				3302	<div class="section">
				3303	<h3><a name="calendar-duration-from-datetime"></a>calendar-duration-from-datetime</h3>
				3304
				3305	<ul>
				3306
				3307	<li>
				3308	<p>Syntax:</p>
				3309
				3310	<div class="source">
				3311	<div class="source">
				3312	<pre>calendar-duration-from-datetime(datetime_expression, duration_expression)
				3313	</pre></div></div></li>
				3314
				3315	<li>
				3316	<p>Gets a user-friendly representation of the duration <tt>duration_expression</tt> based on the given datetime <tt>datetime_expression</tt>.</p></li>
				3317
				3318	<li>Arguments:
				3319
				3320	<ul>
				3321
				3322	<li><tt>datetime_expression</tt> : A <tt>datetime</tt> value to be used as the reference time point.</li>
				3323
				3324	<li><tt>duration_expression</tt> : A <tt>duration</tt> value to be converted.</li>
				3325	</ul></li>
				3326
				3327	<li>Return Value:
				3328
				3329	<ul>
				3330
				3331	<li>A <tt>duration</tt> value with the duration as <tt>duration_expression</tt> but with a user-friendly representation.</li>
				3332	</ul></li>
				3333
				3334	<li>
				3335	<p>Example:</p>
				3336
				3337	<div class="source">
				3338	<div class="source">
				3339	<pre>use dataverse TinySocial;
				3340
				3341	for $i in dataset('TweetMessages')
				3342	where $i.send-time > datetime("2011-01-01T00:00:00")
				3343	return {"since-2011": subtract-datetime($i.send-time, datetime("2011-01-01T00:00:00")), "since-2011-user-friendly": calendar-duration-from-datetime($i.send-time, subtract-datetime($i.send-time, datetime("2011-01-01T00:00:00")))}
				3344	</pre></div></div></li>
				3345	</ul>
				3346
				3347	<ul>
				3348
				3349	<li>
				3350	<p>The expected result is:</p>
				3351
				3352	<div class="source">
				3353	<div class="source">
				3354	<pre>{ "since-2011": duration("P359DT10H10M"), "since-2011-user-friendly": duration("P11M23DT10H10M") }
				3355	{ "since-2011": duration("P236DT10H10M"), "since-2011-user-friendly": duration("P7M23DT10H10M") }
				3356	{ "since-2011": duration("P567DT10H10M"), "since-2011-user-friendly": duration("P1Y6M18DT10H10M") }
				3357	</pre></div></div></li>
				3358	</ul></div>
				3359	<div class="section">
				3360	<h3><a name="get-year-month-durationget-day-time-duration"></a>get-year-month-duration/get-day-time-duration</h3>
				3361
				3362	<ul>
				3363
				3364	<li>
				3365	<p>Syntax:</p>
				3366
				3367	<div class="source">
				3368	<div class="source">
				3369	<pre>get-year-month-duration/get-day-time-duration(duration_expression)
				3370	</pre></div></div></li>
				3371
				3372	<li>
				3373	<p>Extracts the correct <tt>duration</tt> subtype from <tt>duration_expression</tt>.</p></li>
				3374
				3375	<li>Arguments:
				3376
				3377	<ul>
				3378
				3379	<li><tt>duration_expression</tt> : A <tt>duration</tt> value to be converted.</li>
				3380	</ul></li>
				3381
				3382	<li>Return Value:
				3383
				3384	<ul>
				3385
				3386	<li>A <tt>year-month-duration</tt> value or a <tt>day-time-duration</tt> value.</li>
				3387	</ul></li>
				3388
				3389	<li>
				3390	<p>Example:</p>
				3391
				3392	<div class="source">
				3393	<div class="source">
				3394	<pre>let $i := get-year-month-duration(duration("P12M50DT10H"))
				3395	return $i;
				3396	</pre></div></div></li>
				3397	</ul>
				3398
				3399	<ul>
				3400
				3401	<li>
				3402	<p>The expected result is:</p>
				3403
				3404	<div class="source">
				3405	<div class="source">
				3406	<pre>year-month-duration("P1Y")
				3407	</pre></div></div></li>
				3408	</ul></div>
				3409	<div class="section">
				3410	<h3><a name="months-from-year-month-durationmilliseconds-from-day-time-duration"></a>months-from-year-month-duration/milliseconds-from-day-time-duration</h3>
				3411
				3412	<ul>
				3413
				3414	<li>
				3415	<p>Syntax:</p>
				3416
				3417	<div class="source">
				3418	<div class="source">
				3419	<pre>months-from-year-month-duration/milliseconds-from-day-time-duration(duration_expression)
				3420	</pre></div></div></li>
				3421
				3422	<li>
				3423	<p>Extracts the number of months or the number of milliseconds from the <tt>duration</tt> subtype.</p></li>
				3424
				3425	<li>Arguments:
				3426
				3427	<ul>
				3428
				3429	<li><tt>duration_expression</tt> : A <tt>duration</tt> of the correct subtype.</li>
				3430	</ul></li>
				3431
				3432	<li>Return Value:
				3433
				3434	<ul>
				3435
				3436	<li>An <tt>int64</tt> representing the number or months/milliseconds.</li>
				3437	</ul></li>
				3438
				3439	<li>
				3440	<p>Example:</p>
				3441
				3442	<div class="source">
				3443	<div class="source">
				3444	<pre>let $i := months-from-year-month-duration(get-year-month-duration(duration("P5Y7MT50M")))
				3445	return $i;
				3446	</pre></div></div></li>
				3447	</ul>
				3448
				3449	<ul>
				3450
				3451	<li>
				3452	<p>The expected result is:</p>
				3453
				3454	<div class="source">
				3455	<div class="source">
				3456	<pre>67
				3457	</pre></div></div></li>
				3458	</ul></div>
				3459	<div class="section">
				3460	<h3><a name="duration-from-monthsduration-from-ms"></a>duration-from-months/duration-from-ms</h3>
				3461
				3462	<ul>
				3463
				3464	<li>
				3465	<p>Syntax:</p>
				3466
				3467	<div class="source">
				3468	<div class="source">
				3469	<pre>duration-from-months/duration-from-ms(number_expression)
				3470	</pre></div></div></li>
				3471
				3472	<li>
				3473	<p>Creates a <tt>duration</tt> from <tt>number_expression</tt>.</p></li>
				3474
				3475	<li>Arguments:
				3476
				3477	<ul>
				3478
				3479	<li><tt>number_expression</tt> : An <tt>int64</tt> representing the number of months/milliseconds</li>
				3480	</ul></li>
				3481
				3482	<li>Return Value:
				3483
				3484	<ul>
				3485
				3486	<li>A <tt>duration</tt> containing <tt>number_expression</tt> value for months/milliseconds</li>
				3487	</ul></li>
				3488
				3489	<li>
				3490	<p>Example:</p>
				3491
				3492	<div class="source">
				3493	<div class="source">
				3494	<pre>let $i := duration-from-months(8)
				3495	return $i;
				3496	</pre></div></div></li>
				3497
				3498	<li>
				3499	<p>The expected result is:</p>
				3500
				3501	<div class="source">
				3502	<div class="source">
				3503	<pre>duration("P8M")
				3504	</pre></div></div></li>
				3505	</ul></div>
				3506	<div class="section">
				3507	<h3><a name="duration-from-interval"></a>duration-from-interval</h3>
				3508
				3509	<ul>
				3510
				3511	<li>
				3512	<p>Syntax:</p>
				3513
				3514	<div class="source">
				3515	<div class="source">
				3516	<pre>duration-from-interval(interval_expression)
				3517	</pre></div></div></li>
				3518
				3519	<li>
				3520	<p>Creates a <tt>duration</tt> from <tt>interval_expression</tt>.</p></li>
				3521
				3522	<li>Arguments:
				3523
				3524	<ul>
				3525
				3526	<li><tt>interval_expression</tt> : An <tt>interval</tt> value</li>
				3527	</ul></li>
				3528
				3529	<li>Return Value:
				3530
				3531	<ul>
				3532
				3533	<li>A <tt>duration</tt> repesenting the time in the <tt>interval_expression</tt></li>
				3534	</ul></li>
				3535
				3536	<li>
				3537	<p>Example:</p>
				3538
				3539	<div class="source">
				3540	<div class="source">
				3541	<pre>let $itv1 := interval-from-date("2010-10-30", "2010-12-21")
				3542	let $itv2 := interval-from-datetime("2012-06-26T01:01:01.111", "2012-07-27T02:02:02.222")
				3543	let $itv3 := interval-from-time("12:32:38", "20:29:20")
				3544
				3545	return { "dr1" : duration-from-interval($itv1),
				3546	"dr2" : duration-from-interval($itv2),
				3547	"dr3" : duration-from-interval($itv3),
				3548	"dr4" : duration-from-interval(null) }
				3549	</pre></div></div></li>
				3550
				3551	<li>
				3552	<p>The expected result is:</p>
				3553
				3554	<div class="source">
				3555	<div class="source">
				3556	<pre>{ "dr1": day-time-duration("P52D"),
				3557	"dr2": day-time-duration("P31DT1H1M1.111S"),
				3558	"dr3": day-time-duration("PT7H56M42S"),
				3559	"dr4": null }
				3560	</pre></div></div></li>
				3561	</ul></div>
				3562	<div class="section">
				3563	<h3><a name="current-date"></a>current-date</h3>
				3564
				3565	<ul>
				3566
				3567	<li>
				3568	<p>Syntax:</p>
				3569
				3570	<div class="source">
				3571	<div class="source">
				3572	<pre>current-date()
				3573	</pre></div></div></li>
				3574
				3575	<li>
				3576	<p>Gets the current date.</p></li>
				3577
				3578	<li>Arguments: None</li>
				3579
				3580	<li>Return Value:
				3581
				3582	<ul>
				3583
				3584	<li>A <tt>date</tt> value of the date when the function is called.</li>
				3585	</ul></li>
				3586	</ul></div>
				3587	<div class="section">
				3588	<h3><a name="current-time"></a>current-time</h3>
				3589
				3590	<ul>
				3591
				3592	<li>
				3593	<p>Syntax:</p>
				3594
				3595	<div class="source">
				3596	<div class="source">
				3597	<pre>current-time()
				3598	</pre></div></div></li>
				3599
				3600	<li>
				3601	<p>Get the current time</p></li>
				3602
				3603	<li>Arguments: None</li>
				3604
				3605	<li>Return Value:
				3606
				3607	<ul>
				3608
				3609	<li>A <tt>time</tt> value of the time when the function is called.</li>
				3610	</ul></li>
				3611	</ul></div>
				3612	<div class="section">
				3613	<h3><a name="current-datetime"></a>current-datetime</h3>
				3614
				3615	<ul>
				3616
				3617	<li>
				3618	<p>Syntax:</p>
				3619
				3620	<div class="source">
				3621	<div class="source">
				3622	<pre>current-datetime()
				3623	</pre></div></div></li>
				3624
				3625	<li>
				3626	<p>Get the current datetime</p></li>
				3627
				3628	<li>Arguments: None</li>
				3629
				3630	<li>Return Value:
				3631
				3632	<ul>
				3633
				3634	<li>A <tt>datetime</tt> value of the datetime when the function is called.</li>
				3635	</ul></li>
				3636
				3637	<li>
				3638	<p>Example:</p>
				3639
				3640	<div class="source">
				3641	<div class="source">
				3642	<pre>{"current-date": current-date(),
				3643	"current-time": current-time(),
				3644	"current-datetime": current-datetime()}
				3645	</pre></div></div></li>
				3646	</ul>
				3647
				3648	<ul>
				3649
				3650	<li>
				3651	<p>The expected result is:</p>
				3652
				3653	<div class="source">
				3654	<div class="source">
				3655	<pre>{ "current-date": date("2013-04-06"),
				3656	"current-time": time("00:48:44.093Z"),
				3657	"current-datetime": datetime("2013-04-06T00:48:44.093Z") }
				3658	</pre></div></div></li>
				3659	</ul></div>
				3660	<div class="section">
				3661	<h3><a name="get-date-from-datetime"></a>get-date-from-datetime</h3>
				3662
				3663	<ul>
				3664
				3665	<li>
				3666	<p>Syntax:</p>
				3667
				3668	<div class="source">
				3669	<div class="source">
				3670	<pre>get-date-from-datetime(datetime_expression)
				3671	</pre></div></div></li>
				3672
				3673	<li>
				3674	<p>Gets the date value from the given datetime value <tt>datetime_expression</tt>.</p></li>
				3675
				3676	<li>Arguments:
				3677
				3678	<ul>
				3679
				3680	<li><tt>datetime_expression</tt>: A <tt>datetime</tt> value to be extracted from.</li>
				3681	</ul></li>
				3682
				3683	<li>Return Value:
				3684
				3685	<ul>
				3686
				3687	<li>A <tt>date</tt> value from the datetime.</li>
				3688	</ul></li>
				3689	</ul></div>
				3690	<div class="section">
				3691	<h3><a name="get-time-from-datetime"></a>get-time-from-datetime</h3>
				3692
				3693	<ul>
				3694
				3695	<li>
				3696	<p>Syntax:</p>
				3697
				3698	<div class="source">
				3699	<div class="source">
				3700	<pre>get-time-from-datetime(datetime_expression)
				3701	</pre></div></div></li>
				3702
				3703	<li>
				3704	<p>Get the time value from the given datetime value <tt>datetime_expression</tt></p></li>
				3705
				3706	<li>Arguments:
				3707
				3708	<ul>
				3709
				3710	<li><tt>datetime_expression</tt>: A <tt>datetime</tt> value to be extracted from</li>
				3711	</ul></li>
				3712
				3713	<li>Return Value:
				3714
				3715	<ul>
				3716
				3717	<li>A <tt>time</tt> value from the datetime.</li>
				3718	</ul></li>
				3719
				3720	<li>
				3721	<p>Example:</p>
				3722
				3723	<div class="source">
				3724	<div class="source">
				3725	<pre>use dataverse TinySocial;
				3726
				3727	for $i in dataset('TweetMessages')
				3728	where $i.send-time > datetime("2011-01-01T00:00:00")
				3729	return {"send-date": get-date-from-datetime($i.send-time), "send-time": get-time-from-datetime($i.send-time)}
				3730	</pre></div></div></li>
				3731	</ul>
				3732
				3733	<ul>
				3734
				3735	<li>
				3736	<p>The expected result is:</p>
				3737
				3738	<div class="source">
				3739	<div class="source">
				3740	<pre>{ "send-date": date("2011-12-26"), "send-time": time("10:10:00.000Z") }
				3741	{ "send-date": date("2011-08-25"), "send-time": time("10:10:00.000Z") }
				3742	{ "send-date": date("2012-07-21"), "send-time": time("10:10:00.000Z") }
				3743	</pre></div></div></li>
				3744	</ul></div>
				3745	<div class="section">
				3746	<h3><a name="day-of-week"></a>day-of-week</h3>
				3747
				3748	<ul>
				3749
				3750	<li>
				3751	<p>Syntax:</p>
				3752
				3753	<div class="source">
				3754	<div class="source">
				3755	<pre>day-of-week(date_expression)
				3756	</pre></div></div></li>
				3757
				3758	<li>
				3759	<p>Finds the day of the week for a given date (1-7)</p></li>
				3760
				3761	<li>Arguments:
				3762
				3763	<ul>
				3764
				3765	<li><tt>date_expression</tt>: A <tt>date</tt> value (Can also be a <tt>datetime</tt>)</li>
				3766	</ul></li>
				3767
				3768	<li>Return Value:
				3769
				3770	<ul>
				3771
				3772	<li>An <tt>int8</tt> representing the day of the week (1-7)</li>
				3773	</ul></li>
				3774
				3775	<li>
				3776	<p>Example:</p>
				3777
				3778	<div class="source">
				3779	<div class="source">
				3780	<pre>let $i := day-of-week( datetime("2012-12-30T12:12:12.039Z"))
				3781	return $i;
				3782	</pre></div></div></li>
				3783	</ul>
				3784
				3785	<ul>
				3786
				3787	<li>
				3788	<p>The expected result is:</p>
				3789
				3790	<div class="source">
				3791	<div class="source">
				3792	<pre>7
				3793	</pre></div></div></li>
				3794	</ul></div>
				3795	<div class="section">
				3796	<h3><a name="date-from-unix-time-in-days"></a>date-from-unix-time-in-days</h3>
				3797
				3798	<ul>
				3799
				3800	<li>
				3801	<p>Syntax:</p>
				3802
				3803	<div class="source">
				3804	<div class="source">
				3805	<pre>date-from-unix-time-in-days(numeric_expression)
				3806	</pre></div></div></li>
				3807
				3808	<li>
				3809	<p>Gets a date representing the time after <tt>numeric_expression</tt> days since 1970-01-01.</p></li>
				3810
				3811	<li>Arguments:
				3812
				3813	<ul>
				3814
				3815	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt> value representing the number of days.</li>
				3816	</ul></li>
				3817
				3818	<li>Return Value:
				3819
				3820	<ul>
				3821
				3822	<li>A <tt>date</tt> value as the time after <tt>numeric_expression</tt> days since 1970-01-01.</li>
				3823	</ul></li>
				3824	</ul></div>
				3825	<div class="section">
				3826	<h3><a name="datetime-from-unix-time-in-ms"></a>datetime-from-unix-time-in-ms</h3>
				3827
				3828	<ul>
				3829
				3830	<li>
				3831	<p>Syntax:</p>
				3832
				3833	<div class="source">
				3834	<div class="source">
				3835	<pre>datetime-from-unix-time-in-ms(numeric_expression)
				3836	</pre></div></div></li>
				3837
				3838	<li>
				3839	<p>Gets a datetime representing the time after <tt>numeric_expression</tt> milliseconds since 1970-01-01T00:00:00Z.</p></li>
				3840
				3841	<li>Arguments:
				3842
				3843	<ul>
				3844
				3845	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt> value representing the number of milliseconds.</li>
				3846	</ul></li>
				3847
				3848	<li>Return Value:
				3849
				3850	<ul>
				3851
				3852	<li>A <tt>datetime</tt> value as the time after <tt>numeric_expression</tt> milliseconds since 1970-01-01T00:00:00Z.</li>
				3853	</ul></li>
				3854	</ul></div>
				3855	<div class="section">
				3856	<h3><a name="datetime-from-unix-time-in-secs"></a>datetime-from-unix-time-in-secs</h3>
				3857
				3858	<ul>
				3859
				3860	<li>
				3861	<p>Syntax:</p>
				3862
				3863	<div class="source">
				3864	<div class="source">
				3865	<pre>datetime-from-unix-time-in-secs(numeric_expression)
				3866	</pre></div></div></li>
				3867
				3868	<li>
				3869	<p>Gets a datetime representing the time after <tt>numeric_expression</tt> seconds since 1970-01-01T00:00:00Z.</p></li>
				3870
				3871	<li>Arguments:
				3872
				3873	<ul>
				3874
				3875	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt> value representing the number of seconds.</li>
				3876	</ul></li>
				3877
				3878	<li>Return Value:
				3879
				3880	<ul>
				3881
				3882	<li>A <tt>datetime</tt> value as the time after <tt>numeric_expression</tt> seconds since 1970-01-01T00:00:00Z.</li>
				3883	</ul></li>
				3884	</ul></div>
				3885	<div class="section">
				3886	<h3><a name="datetime-from-date-time"></a>datetime-from-date-time</h3>
				3887
				3888	<ul>
				3889
				3890	<li>Syntax:</li>
				3891	</ul>
				3892	<p>datetime-from-date-time(date_expression,time_expression)</p>
				3893
				3894	<ul>
				3895
				3896	<li>Gets a datetime representing the combination of <tt>date_expression</tt> and <tt>time_expression</tt>
				3897
				3898	<ul>
				3899
				3900	<li>Arguments:</li>
				3901
				3902	<li><tt>date_expression</tt>: A <tt>date</tt> value</li>
				3903
				3904	<li><tt>time_expression</tt> A <tt>time</tt> value</li>
				3905	</ul></li>
				3906
				3907	<li>Return Value:
				3908
				3909	<ul>
				3910
				3911	<li>A <tt>datetime</tt> value by combining <tt>date_expression</tt> and <tt>time_expression</tt></li>
				3912	</ul></li>
				3913	</ul></div>
				3914	<div class="section">
				3915	<h3><a name="time-from-unix-time-in-ms"></a>time-from-unix-time-in-ms</h3>
				3916
				3917	<ul>
				3918
				3919	<li>
				3920	<p>Syntax:</p>
				3921
				3922	<div class="source">
				3923	<div class="source">
				3924	<pre>time-from-unix-time-in-ms(numeric_expression)
				3925	</pre></div></div></li>
				3926
				3927	<li>
				3928	<p>Gets a time representing the time after <tt>numeric_expression</tt> milliseconds since 00:00:00.000Z.</p></li>
				3929
				3930	<li>Arguments:
				3931
				3932	<ul>
				3933
				3934	<li><tt>numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt> value representing the number of milliseconds.</li>
				3935	</ul></li>
				3936
				3937	<li>Return Value:
				3938
				3939	<ul>
				3940
				3941	<li>A <tt>time</tt> value as the time after <tt>numeric_expression</tt> milliseconds since 00:00:00.000Z.</li>
				3942	</ul></li>
				3943
				3944	<li>
				3945	<p>Example:</p>
				3946
				3947	<div class="source">
				3948	<div class="source">
				3949	<pre>use dataverse TinySocial;
				3950
				3951	let $d := date-from-unix-time-in-days(15800)
				3952	let $dt := datetime-from-unix-time-in-ms(1365139700000)
				3953	let $t := time-from-unix-time-in-ms(3748)
				3954	return {"date": $d, "datetime": $dt, "time": $t}
				3955	</pre></div></div></li>
				3956	</ul>
				3957
				3958	<ul>
				3959
				3960	<li>
				3961	<p>The expected result is:</p>
				3962
				3963	<div class="source">
				3964	<div class="source">
				3965	<pre>{ "date": date("2013-04-05"), "datetime": datetime("2013-04-05T05:28:20.000Z"), "time": time("00:00:03.748Z") }
				3966	</pre></div></div></li>
				3967	</ul></div>
				3968	<div class="section">
				3969	<h3><a name="parse-dateparse-timeparse-datetime"></a>parse-date/parse-time/parse-datetime</h3>
				3970
				3971	<ul>
				3972
				3973	<li>Syntax:</li>
				3974	</ul>
				3975	<p>parse-date/parse-time/parse-datetime(date_expression,formatting_expression)</p>
				3976
				3977	<ul>
				3978
				3979	<li>Creates a <tt>date/time/date-time</tt> value by treating <tt>date_expression</tt> with formatting <tt>formatting_expression</tt></li>
				3980
				3981	<li>Arguments:
				3982
				3983	<ul>
				3984
				3985	<li><tt>date_expression</tt>: A <tt>string</tt> value representing the <tt>date/time/datetime</tt>.</li>
				3986
				3987	<li><tt>formatting_expression</tt> A <tt>string</tt> value providing the formatting for <tt>date_expression</tt>.Characters used to create date expression:</li>
				3988
				3989	<li><tt>h</tt> hours</li>
				3990
				3991	<li><tt>m</tt> minutes</li>
				3992
				3993	<li><tt>s</tt> seconds</li>
				3994
				3995	<li><tt>n</tt> milliseconds</li>
				3996
				3997	<li><tt>a</tt> am/pm</li>
				3998
				3999	<li><tt>z</tt> timezone</li>
				4000
				4001	<li><tt>Y</tt> year</li>
				4002
				4003	<li><tt>M</tt> month</li>
				4004
				4005	<li><tt>D</tt> day</li>
				4006
				4007	<li><tt>W</tt> weekday</li>
				4008
				4009	<li><tt>-</tt>, <tt>'</tt>, <tt>/</tt>, <tt>.</tt>, <tt>,</tt>, <tt>T</tt> seperators for both time and date</li>
				4010	</ul></li>
				4011
				4012	<li>Return Value:
				4013
				4014	<ul>
				4015
				4016	<li>A <tt>date/time/date-time</tt> value corresponding to <tt>date_expression</tt></li>
				4017	</ul></li>
				4018
				4019	<li>
				4020	<p>Example:</p>
				4021
				4022	<div class="source">
				4023	<div class="source">
				4024	<pre>let $i := parse-time("30:30","m:s")
				4025	return $i;
				4026	</pre></div></div></li>
				4027
				4028	<li>
				4029	<p>The expected result is:</p>
				4030
				4031	<div class="source">
				4032	<div class="source">
				4033	<pre>time("00:30:30.000Z")
				4034	</pre></div></div></li>
				4035	</ul></div>
				4036	<div class="section">
				4037	<h3><a name="print-dateprint-timeprint-datetime"></a>print-date/print-time/print-datetime</h3>
				4038
				4039	<ul>
				4040
				4041	<li>Syntax:</li>
				4042	</ul>
				4043	<p>print-date/print-time/print-datetime(date_expression,formatting_expression)</p>
				4044
				4045	<ul>
				4046
				4047	<li>Creates a <tt>string</tt> representing a <tt>date/time/date-time</tt> value of the <tt>date_expression</tt> using the formatting <tt>formatting_expression</tt></li>
				4048
				4049	<li>Arguments:
				4050
				4051	<ul>
				4052
				4053	<li><tt>date_expression</tt>: A <tt>date/time/datetime</tt> value.</li>
				4054
				4055	<li><tt>formatting_expression</tt> A <tt>string</tt> value providing the formatting for <tt>date_expression</tt>. Characters used to create date expression:</li>
				4056
				4057	<li><tt>h</tt> hours</li>
				4058
				4059	<li><tt>m</tt> minutes</li>
				4060
				4061	<li><tt>s</tt> seconds</li>
				4062
				4063	<li><tt>n</tt> milliseconds</li>
				4064
				4065	<li><tt>a</tt> am/pm</li>
				4066
				4067	<li><tt>z</tt> timezone</li>
				4068
				4069	<li><tt>Y</tt> year</li>
				4070
				4071	<li><tt>M</tt> month</li>
				4072
				4073	<li><tt>D</tt> day</li>
				4074
				4075	<li><tt>W</tt> weekday</li>
				4076
				4077	<li><tt>-</tt>, <tt>'</tt>, <tt>/</tt>, <tt>.</tt>, <tt>,</tt>, <tt>T</tt> seperators for both time and date</li>
				4078	</ul></li>
				4079
				4080	<li>Return Value:
				4081
				4082	<ul>
				4083
				4084	<li>A <tt>string</tt> value corresponding to <tt>date_expression</tt></li>
				4085	</ul></li>
				4086
				4087	<li>
				4088	<p>Example:</p>
				4089
				4090	<div class="source">
				4091	<div class="source">
				4092	<pre>let $i := print-time(time("00:30:30.000Z"),"m:s")
				4093	return $i;
				4094	</pre></div></div></li>
				4095
				4096	<li>
				4097	<p>The expected result is:</p>
				4098
				4099	<div class="source">
				4100	<div class="source">
				4101	<pre>"30:30"
				4102	</pre></div></div></li>
				4103	</ul></div>
				4104	<div class="section">
				4105	<h3><a name="get-interval-start_get-interval-end"></a>get-interval-start, get-interval-end</h3>
				4106
				4107	<ul>
				4108
				4109	<li>
				4110	<p>Syntax:</p>
				4111
				4112	<div class="source">
				4113	<div class="source">
				4114	<pre>get-interval-start/get-interval-end(interval)
				4115	</pre></div></div></li>
				4116
				4117	<li>
				4118	<p>Gets the start/end of the given interval.</p></li>
				4119
				4120	<li>Arguments:
				4121
				4122	<ul>
				4123
				4124	<li><tt>interval</tt>: the interval to be accessed.</li>
				4125	</ul></li>
				4126
				4127	<li>Return Value:
				4128
				4129	<ul>
				4130
				4131	<li>A <tt>time</tt>, <tt>date</tt>, or <tt>datetime</tt> (depending on the time instances of the interval) representing the starting or ending time.</li>
				4132	</ul></li>
				4133
				4134	<li>
				4135	<p>Example:</p>
				4136
				4137	<div class="source">
				4138	<div class="source">
				4139	<pre>let $itv := interval-start-from-date("1984-01-01", "P1Y")
				4140	return {"start": get-interval-start($itv), "end": get-interval-end($itv)}
				4141	</pre></div></div></li>
				4142	</ul>
				4143
				4144	<ul>
				4145
				4146	<li>
				4147	<p>The expected result is:</p>
				4148
				4149	<div class="source">
				4150	<div class="source">
				4151	<pre>{ "start": date("1984-01-01"), "end": date("1985-01-01") }
				4152	</pre></div></div></li>
				4153	</ul></div>
				4154	<div class="section">
				4155	<h3><a name="get-interval-start-dateget-interval-start-datetimeget-interval-start-time_get-interval-end-dateget-interval-end-datetimeget-interval-end-time"></a>get-interval-start-date/get-interval-start-datetimeget-interval-start-time, get-interval-end-date/get-interval-end-datetime/get-interval-end-time</h3>
				4156
				4157	<ul>
				4158
				4159	<li>
				4160	<p>Syntax:</p>
				4161
				4162	<div class="source">
				4163	<div class="source">
				4164	<pre>get-interval-start-date/get-interval-start-datetime/get-interval-start-time/get-interval-end-date/get-interval-end-datetime/get-interval-end-time(interval)
				4165	</pre></div></div></li>
				4166
				4167	<li>
				4168	<p>Gets the start/end of the given interval for the specific date/datetime/time type.</p></li>
				4169
				4170	<li>Arguments:
				4171
				4172	<ul>
				4173
				4174	<li><tt>interval</tt>: the interval to be accessed.</li>
				4175	</ul></li>
				4176
				4177	<li>Return Value:
				4178
				4179	<ul>
				4180
				4181	<li>A <tt>time</tt>, <tt>date</tt>, or <tt>datetime</tt> (depending on the function) representing the starting or ending time.</li>
				4182	</ul></li>
				4183
				4184	<li>
				4185	<p>Example:</p>
				4186
				4187	<div class="source">
				4188	<div class="source">
				4189	<pre>let $itv1 := interval-start-from-date("1984-01-01", "P1Y")
				4190	let $itv2 := interval-start-from-datetime("1984-01-01T08:30:00.000", "P1Y1H")
				4191	let $itv3 := interval-start-from-time("08:30:00.000", "P1H")
				4192	return {"start": get-interval-start-date($itv1), "end": get-interval-end-date($itv1), "start": get-interval-start-datetime($itv2), "end": get-interval-end-datetime($itv2), "start": get-interval-start-time($itv3), "end": get-interval-end-time($itv3)}
				4193	</pre></div></div></li>
				4194	</ul>
				4195
				4196	<ul>
				4197
				4198	<li>
				4199	<p>The expected result is:</p>
				4200
				4201	<div class="source">
				4202	<div class="source">
				4203	<pre>{ "start": date("1984-01-01"), "end": date("1985-01-01"), "start": datetime("1984-01-01T08:30:00.000"), "end": datetime("1984-02-01T09:30:00.000"), "start": date("08:30:00.000"), "end": time("09:30:00.000") }
				4204	</pre></div></div></li>
				4205	</ul></div>
				4206	<div class="section">
				4207	<h3><a name="get-overlapping-interval"></a>get-overlapping-interval</h3>
				4208
				4209	<ul>
				4210
				4211	<li>
				4212	<p>Syntax:</p>
				4213
				4214	<div class="source">
				4215	<div class="source">
				4216	<pre>get-overlapping-interval(interval_expression_1, interval_expression_2)
				4217	</pre></div></div></li>
				4218
				4219	<li>
				4220	<p>Gets the start/end of the given interval for the specific date/datetime/time type.</p></li>
				4221
				4222	<li>Arguments:
				4223
				4224	<ul>
				4225
				4226	<li><tt>interval_expression_1</tt>: an <tt>interval</tt> value</li>
				4227
				4228	<li><tt>interval_expression_2</tt>: an <tt>interval</tt> value</li>
				4229	</ul></li>
				4230
				4231	<li>Return Value:
				4232
				4233	<ul>
				4234
				4235	<li>Returns an <tt>interval</tt> that is overlapping <tt>interval_expression_1</tt> and <tt>interval_expression_2</tt>. If <tt>interval_expression_1</tt> and <tt>interval_expression_2</tt> do not overlap <tt>null</tt> is returned. Note each interval must be of the same type.</li>
				4236	</ul></li>
				4237
				4238	<li>
				4239	<p>Example:</p>
				4240
				4241	<div class="source">
				4242	<div class="source">
				4243	<pre>{ "overlap1": get-overlapping-interval(interval-from-time(time("11:23:39"), time("18:27:19")), interval-from-time(time("12:23:39"), time("23:18:00"))),
				4244	"overlap2": get-overlapping-interval(interval-from-time(time("12:23:39"), time("18:27:19")), interval-from-time(time("07:19:39"), time("09:18:00"))),
				4245	"overlap3": get-overlapping-interval(interval-from-date(date("1980-11-30"), date("1999-09-09")), interval-from-date(date("2013-01-01"), date("2014-01-01"))),
				4246	"overlap4": get-overlapping-interval(interval-from-date(date("1980-11-30"), date("2099-09-09")), interval-from-date(date("2013-01-01"), date("2014-01-01"))),
				4247	"overlap5": get-overlapping-interval(interval-from-datetime(datetime("1844-03-03T11:19:39"), datetime("2000-10-30T18:27:19")), interval-from-datetime(datetime("1989-03-04T12:23:39"), datetime("2009-10-10T23:18:00"))),
				4248	"overlap6": get-overlapping-interval(interval-from-datetime(datetime("1989-03-04T12:23:39"), datetime("2000-10-30T18:27:19")), interval-from-datetime(datetime("1844-03-03T11:19:39"), datetime("1888-10-10T23:18:00"))) }
				4249	</pre></div></div></li>
				4250
				4251	<li>
				4252	<p>The expected result is:</p>
				4253
				4254	<div class="source">
				4255	<div class="source">
				4256	<pre>{ "overlap1": interval-time("12:23:39.000Z, 18:27:19.000Z"),
				4257	"overlap2": null,
				4258	"overlap3": null,
				4259	"overlap4": interval-date("2013-01-01, 2014-01-01"),
				4260	"overlap5": interval-datetime("1989-03-04T12:23:39.000Z, 2000-10-30T18:27:19.000Z"),
				4261	"overlap6": null }
				4262	</pre></div></div></li>
				4263	</ul></div>
				4264	<div class="section">
				4265	<h3><a name="interval-beforeinterval-afterinterval-meetsinterval-met-byinterval-overlapsinterval-overlapped-byinterval-overlappinginterval-startsinterval-started-byinterval-coversinterval-covered-byinterval-endsinterval-ended-by"></a>interval-before/interval-after/interval-meets/interval-met-by/interval-overlaps/interval-overlapped-by/interval-overlapping/interval-starts/interval-started-by/interval-covers/interval-covered-by/interval-ends/interval-ended-by</h3>
				4266	<p>See the <a href="allens.html">Allen’s Relations</a>.</p></div>
				4267	<div class="section">
				4268	<h3><a name="interval-bin"></a>interval-bin</h3>
				4269
				4270	<ul>
				4271
				4272	<li>
				4273	<p>Syntax:</p>
				4274
				4275	<div class="source">
				4276	<div class="source">
				4277	<pre>interval-bin(time-to-bin, time-bin-anchor, duration-bin-size)
				4278	</pre></div></div></li>
				4279
				4280	<li>
				4281	<p>Return the <tt>interval</tt> value representing the bin containing the <tt>time-to-bin</tt> value.</p></li>
				4282
				4283	<li>Arguments:
				4284
				4285	<ul>
				4286
				4287	<li><tt>time-to-bin</tt>: a date/time/datetime value representing the time to be binned.</li>
				4288
				4289	<li><tt>time-bin-anchor</tt>: a date/time/datetime value representing an anchor of a bin starts. The type of this argument should be the same as the first <tt>time-to-bin</tt> argument.</li>
				4290
				4291	<li><tt>duration-bin-size</tt>: the duration value representing the size of the bin, in the type of year-month-duration or day-time-duration. The type of this duration should be compatible with the type of <tt>time-to-bin</tt>, so that the arithmetic operation between <tt>time-to-bin</tt> and <tt>duration-bin-size</tt> is well-defined. Currently AsterixDB supports the following arithmetic operations:
				4292
				4293	<ul>
				4294
				4295	<li>datetime +\|- year-month-duration</li>
				4296
				4297	<li>datetime +\|- day-time-duration</li>
				4298
				4299	<li>date +\|- year-month-duration</li>
				4300
				4301	<li>date +\|- day-time-duration</li>
				4302
				4303	<li>time +\|- day-time-duration</li>
				4304	</ul></li>
				4305	</ul></li>
				4306
				4307	<li>Return Value:
				4308
				4309	<ul>
				4310
				4311	<li>A <tt>interval</tt> value representing the bin containing the <tt>time-to-bin</tt> value. Note that the internal type of this interval value should be the same as the <tt>time-to-bin</tt> type.</li>
				4312	</ul></li>
				4313
				4314	<li>
				4315	<p>Example:</p>
				4316
				4317	<div class="source">
				4318	<div class="source">
				4319	<pre>let $c1 := date("2010-10-30")
				4320	let $c2 := datetime("-1987-11-19T23:49:23.938")
				4321	let $c3 := time("12:23:34.930+07:00")
				4322
				4323	return { "bin1": interval-bin($c1, date("1990-01-01"), year-month-duration("P1Y")),
				4324	"bin2": interval-bin($c2, datetime("1990-01-01T00:00:00.000Z"), year-month-duration("P6M")),
				4325	"bin3": interval-bin($c3, time("00:00:00"), day-time-duration("PD1M")),
				4326	"bin4": interval-bin($c2, datetime("2013-01-01T00:00:00.000"), day-time-duration("PT24H"))
				4327	</pre></div></div> }</li>
				4328
				4329	<li>
				4330	<p>The expected result is:</p>
				4331
				4332	<div class="source">
				4333	<div class="source">
				4334	<pre>{ "bin1": interval-date("2010-01-01, 2011-01-01"),
				4335	"bin2": interval-datetime("-1987-07-01T00:00:00.000Z, -1986-01-01T00:00:00.000Z"),
				4336	"bin3": interval-time("05:23:00.000Z, 05:24:00.000Z"),
				4337	"bin4": interval-datetime("-1987-11-19T00:00:00.000Z, -1987-11-20T00:00:00.000Z")}
				4338	</pre></div></div></li>
				4339	</ul></div>
				4340	<div class="section">
				4341	<h3><a name="interval-from-date"></a>interval-from-date</h3>
				4342
				4343	<ul>
				4344
				4345	<li>
				4346	<p>Syntax:</p>
				4347
				4348	<div class="source">
				4349	<div class="source">
				4350	<pre>interval-from-date(string_expression1, string_expression2)
				4351	</pre></div></div></li>
				4352
				4353	<li>
				4354	<p>Constructor function for the <tt>interval</tt> type by parsing two date strings.</p></li>
				4355
				4356	<li>Arguments:
				4357
				4358	<ul>
				4359
				4360	<li><tt>string_expression1</tt> : The <tt>string</tt> value representing the starting date.</li>
				4361
				4362	<li><tt>string_expression2</tt> : The <tt>string</tt> value representing the ending date.</li>
				4363	</ul></li>
				4364
				4365	<li>Return Value:
				4366
				4367	<ul>
				4368
				4369	<li>An <tt>interval</tt> value between the two dates.</li>
				4370	</ul></li>
				4371
				4372	<li>
				4373	<p>Example:</p>
				4374
				4375	<div class="source">
				4376	<div class="source">
				4377	<pre>{"date-interval": interval-from-date("2012-01-01", "2013-04-01")}
				4378	</pre></div></div></li>
				4379	</ul>
				4380
				4381	<ul>
				4382
				4383	<li>
				4384	<p>The expected result is:</p>
				4385
				4386	<div class="source">
				4387	<div class="source">
				4388	<pre>{ "date-interval": interval-date("2012-01-01, 2013-04-01") }
				4389	</pre></div></div></li>
				4390	</ul></div>
				4391	<div class="section">
				4392	<h3><a name="interval-from-time"></a>interval-from-time</h3>
				4393
				4394	<ul>
				4395
				4396	<li>
				4397	<p>Syntax:</p>
				4398
				4399	<div class="source">
				4400	<div class="source">
				4401	<pre>interval-from-time(string_expression1, string_expression2)
				4402	</pre></div></div></li>
				4403
				4404	<li>
				4405	<p>Constructor function for the <tt>interval</tt> type by parsing two time strings.</p></li>
				4406
				4407	<li>Arguments:
				4408
				4409	<ul>
				4410
				4411	<li><tt>string_expression1</tt> : The <tt>string</tt> value representing the starting time.</li>
				4412
				4413	<li><tt>string_expression2</tt> : The <tt>string</tt> value representing the ending time.</li>
				4414	</ul></li>
				4415
				4416	<li>Return Value:
				4417
				4418	<ul>
				4419
				4420	<li>An <tt>interval</tt> value between the two times.</li>
				4421	</ul></li>
				4422
				4423	<li>
				4424	<p>Example:</p>
				4425
				4426	<div class="source">
				4427	<div class="source">
				4428	<pre>{"time-interval": interval-from-time("12:23:34.456Z", "233445567+0800")}
				4429	</pre></div></div></li>
				4430	</ul>
				4431
				4432	<ul>
				4433
				4434	<li>
				4435	<p>The expected result is:</p>
				4436
				4437	<div class="source">
				4438	<div class="source">
				4439	<pre>{ "time-interval": interval-time("12:23:34.456Z, 15:34:45.567Z") }
				4440	</pre></div></div></li>
				4441	</ul></div>
				4442	<div class="section">
				4443	<h3><a name="interval-from-datetime"></a>interval-from-datetime</h3>
				4444
				4445	<ul>
				4446
				4447	<li>
				4448	<p>Syntax:</p>
				4449
				4450	<div class="source">
				4451	<div class="source">
				4452	<pre>interval-from-datetime(string_expression1, string_expression2)
				4453	</pre></div></div></li>
				4454
				4455	<li>
				4456	<p>Constructor function for <tt>interval</tt> type by parsing two datetime strings.</p></li>
				4457
				4458	<li>Arguments:
				4459
				4460	<ul>
				4461
				4462	<li><tt>string_expression1</tt> : The <tt>string</tt> value representing the starting datetime.</li>
				4463
				4464	<li><tt>string_expression2</tt> : The <tt>string</tt> value representing the ending datetime.</li>
				4465	</ul></li>
				4466
				4467	<li>Return Value:
				4468
				4469	<ul>
				4470
				4471	<li>An <tt>interval</tt> value between the two datetimes.</li>
				4472	</ul></li>
				4473
				4474	<li>
				4475	<p>Example:</p>
				4476
				4477	<div class="source">
				4478	<div class="source">
				4479	<pre>{"datetime-interval": interval-from-datetime("2012-01-01T12:23:34.456+08:00", "20130401T153445567Z")}
				4480	</pre></div></div></li>
				4481	</ul>
				4482
				4483	<ul>
				4484
				4485	<li>
				4486	<p>The expected result is:</p>
				4487
				4488	<div class="source">
				4489	<div class="source">
				4490	<pre>{ "datetime-interval": interval-datetime("2012-01-01T04:23:34.456Z, 2013-04-01T15:34:45.567Z") }
				4491	</pre></div></div></li>
				4492	</ul></div>
				4493	<div class="section">
				4494	<h3><a name="interval-start-from-datetimedatetime"></a>interval-start-from-date/time/datetime</h3>
				4495
				4496	<ul>
				4497
				4498	<li>
				4499	<p>Syntax:</p>
				4500
				4501	<div class="source">
				4502	<div class="source">
				4503	<pre>interval-start-from-date/time/datetime(date/time/datetime, duration)
				4504	</pre></div></div></li>
				4505
				4506	<li>
				4507	<p>Construct an <tt>interval</tt> value by the given starting <tt>date</tt>/<tt>time</tt>/<tt>datetime</tt> and the <tt>duration</tt> that the interval lasts.</p></li>
				4508
				4509	<li>Arguments:
				4510
				4511	<ul>
				4512
				4513	<li><tt>date/time/datetime</tt>: a <tt>string</tt> representing a <tt>date</tt>, <tt>time</tt> or <tt>datetime</tt>, or a <tt>date</tt>/<tt>time</tt>/<tt>datetime</tt> value, representing the starting time point.</li>
				4514
				4515	<li><tt>duration</tt>: a <tt>string</tt> or <tt>duration</tt> value representing the duration of the interval. Note that duration cannot be negative value.</li>
				4516	</ul></li>
				4517
				4518	<li>Return Value:
				4519
				4520	<ul>
				4521
				4522	<li>An <tt>interval</tt> value representing the interval starting from the given time point with the length of duration.</li>
				4523	</ul></li>
				4524
				4525	<li>
				4526	<p>Example:</p>
				4527
				4528	<div class="source">
				4529	<div class="source">
				4530	<pre>let $itv1 := interval-start-from-date("1984-01-01", "P1Y")
				4531	let $itv2 := interval-start-from-time(time("02:23:28.394"), "PT3H24M")
				4532	let $itv3 := interval-start-from-datetime("1999-09-09T09:09:09.999", duration("P2M30D"))
				4533	return {"interval1": $itv1, "interval2": $itv2, "interval3": $itv3}
				4534	</pre></div></div></li>
				4535
				4536	<li>
				4537	<p>The expectecd result is:</p>
				4538
				4539	<div class="source">
				4540	<div class="source">
				4541	<pre>{ "interval1": interval-date("1984-01-01, 1985-01-01"), "interval2": interval-time("02:23:28.394Z, 05:47:28.394Z"), "interval3": interval-datetime("1999-09-09T09:09:09.999Z, 1999-12-09T09:09:09.999Z") }
				4542	</pre></div></div></li>
				4543	</ul></div>
				4544	<div class="section">
				4545	<h3><a name="overlap-bins"></a>overlap-bins</h3>
				4546
				4547	<ul>
				4548
				4549	<li>
				4550	<p>Return Value:</p>
				4551
				4552	<ul>
				4553
				4554	<li>A <tt>interval</tt> value representing the bin containing the <tt>time-to-bin</tt> value. Note that the internal type of this interval value should be the same as the <tt>time-to-bin</tt> type.</li>
				4555	</ul></li>
				4556
				4557	<li>
				4558	<p>Syntax:</p>
				4559
				4560	<div class="source">
				4561	<div class="source">
				4562	<pre>overlap-bins(interval_expression, time-bin-anchor, duration-bin-size)
				4563	</pre></div></div></li>
				4564
				4565	<li>
				4566	<p>Returns an ordered list of <tt>interval</tt> values representing each bin that is overlapping the <tt>interval_expression</tt>.</p></li>
				4567
				4568	<li>Arguments:
				4569
				4570	<ul>
				4571
				4572	<li><tt>interval_expression</tt>: an <tt>interval</tt> value</li>
				4573
				4574	<li><tt>time-bin-anchor</tt>: a date/time/datetime value representing an anchor of a bin starts. The type of this argument should be the same as the first <tt>time-to-bin</tt> argument.</li>
				4575
				4576	<li><tt>duration-bin-size</tt>: the duration value representing the size of the bin, in the type of year-month-duration or day-time-duration. The type of this duration should be compatible with the type of <tt>time-to-bin</tt>, so that the arithmetic operation between <tt>time-to-bin</tt> and <tt>duration-bin-size</tt> is well-defined. Currently AsterixDB supports the following arithmetic operations:
				4577
				4578	<ul>
				4579
				4580	<li>datetime +\|- year-month-duration</li>
				4581
				4582	<li>datetime +\|- day-time-duration</li>
				4583
				4584	<li>date +\|- year-month-duration</li>
				4585
				4586	<li>date +\|- day-time-duration</li>
				4587
				4588	<li>time +\|- day-time-duration</li>
				4589	</ul></li>
				4590	</ul></li>
				4591
				4592	<li>Return Value:
				4593
				4594	<ul>
				4595
				4596	<li>A ordered list of <tt>interval</tt> values representing each bin that is overlapping the <tt>interval_expression</tt>. Note that the internal type as <tt>time-to-bin</tt> and <tt>duration-bin-size</tt>.</li>
				4597	</ul></li>
				4598
				4599	<li>
				4600	<p>Example:</p>
				4601
				4602	<div class="source">
				4603	<div class="source">
				4604	<pre>let $itv1 := interval-from-time(time("17:23:37"), time("18:30:21"))
				4605	let $itv2 := interval-from-date(date("1984-03-17"), date("2013-08-22"))
				4606	let $itv3 := interval-from-datetime(datetime("1800-01-01T23:59:48.938"), datetime("2015-07-26T13:28:30.218"))
				4607	return { "timebins": overlap-bins($itv1, time("00:00:00"), day-time-duration("PT30M")),
				4608	"datebins": overlap-bins($itv2, date("1990-01-01"), year-month-duration("P20Y")),
				4609	"datetimebins": overlap-bins($itv3, datetime("1900-01-01T00:00:00.000"), year-month-duration("P100Y")) }
				4610	</pre></div></div></li>
				4611
				4612	<li>
				4613	<p>The expected result is:</p>
				4614
				4615	<div class="source">
				4616	<div class="source">
				4617	<pre>{ "timebins": [ interval-time("17:00:00.000Z, 17:30:00.000Z"), interval-time("17:30:00.000Z, 18:00:00.000Z"), interval-time("18:00:00.000Z, 18:30:00.000Z"), interval-time("18:30:00.000Z, 19:00:00.000Z") ],
				4618	"datebins": [ interval-date("1970-01-01, 1990-01-01"), interval-date("1990-01-01, 2010-01-01"), interval-date("2010-01-01, 2030-01-01") ],
				4619	"datetimebins": [ interval-datetime("1800-01-01T00:00:00.000Z, 1900-01-01T00:00:00.000Z"), interval-datetime("1900-01-01T00:00:00.000Z, 2000-01-01T00:00:00.000Z"), interval-datetime("2000-01-01T00:00:00.000Z, 2100-01-01T00:00:00.000Z") ] }
				4620	</pre></div></div></li>
				4621	</ul></div></div>
				4622	<div class="section">
				4623	<h2><a name="Record_Functions_Back_to_TOC"></a><a name="RecordFunctions" id="RecordFunctions">Record Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				4624	<div class="section">
				4625	<h3><a name="get-record-fields"></a>get-record-fields</h3>
				4626
				4627	<ul>
				4628
				4629	<li>
				4630	<p>Syntax:</p>
				4631
				4632	<div class="source">
				4633	<div class="source">
				4634	<pre>get-record-fields(record_expression)
				4635	</pre></div></div></li>
				4636
				4637	<li>
				4638	<p>Access the record field names, type and open status for a given record.</p></li>
				4639
				4640	<li>Arguments:
				4641
				4642	<ul>
				4643
				4644	<li><tt>record_expression</tt> : a record value.</li>
				4645	</ul></li>
				4646
				4647	<li>Return Value:
				4648
				4649	<ul>
				4650
				4651	<li>An order list of <tt>record</tt> values that include the field-name <tt>string</tt>, field-type <tt>string</tt>, is-open <tt>boolean</tt> and optional nested <tt>orderedList</tt> for the values of a nested record.</li>
				4652	</ul></li>
				4653
				4654	<li>
				4655	<p>Example:</p>
				4656
				4657	<div class="source">
				4658	<div class="source">
				4659	<pre>let $r1 := {"id": 1,
				4660	"project": "AsterixDB",
				4661	"address": {"city": "Irvine", "state": "CA"},
				4662	"related": ["Hivestrix", "Preglix", "Apache VXQuery"] }
				4663	return get-record-fields($r1)
				4664	</pre></div></div></li>
				4665
				4666	<li>
				4667	<p>The expected result is:</p>
				4668
				4669	<div class="source">
				4670	<div class="source">
				4671	<pre>[ { "field-name": "id", "field-type": "INT64", "is-open": false },
				4672	{ "field-name": "project", "field-type": "STRING", "is-open": false },
				4673	{ "field-name": "address", "field-type": "RECORD", "is-open": false, "nested": [
				4674	{ "field-name": "city", "field-type": "STRING", "is-open": false },
				4675	{ "field-name": "state", "field-type": "STRING", "is-open": false } ] },
				4676	{ "field-name": "related", "field-type": "ORDEREDLIST", "is-open": false, "list": [
				4677	{ "field-type": "STRING" },
				4678	{ "field-type": "STRING" },
				4679	{ "field-type": "STRING" } ] } ]
				4680	</pre></div></div></li>
				4681	</ul>
				4682	<p>]</p></div>
				4683	<div class="section">
				4684	<h3><a name="get-record-field-value"></a>get-record-field-value</h3>
				4685
				4686	<ul>
				4687
				4688	<li>
				4689	<p>Syntax:</p>
				4690
				4691	<div class="source">
				4692	<div class="source">
				4693	<pre>get-record-field-value(record_expression, string_expression)
				4694	</pre></div></div></li>
				4695
				4696	<li>
				4697	<p>Access the field name given in the <tt>string_expression</tt> from the <tt>record_expression</tt>.</p></li>
				4698
				4699	<li>Arguments:
				4700
				4701	<ul>
				4702
				4703	<li><tt>record_expression</tt> : A <tt>record</tt> value.</li>
				4704
				4705	<li><tt>string_expression</tt> : A <tt>string</tt> representing the top level field name.</li>
				4706	</ul></li>
				4707
				4708	<li>Return Value:
				4709
				4710	<ul>
				4711
				4712	<li>An <tt>any</tt> value saved in the designated field of the record.</li>
				4713	</ul></li>
				4714
				4715	<li>
				4716	<p>Example:</p>
				4717
				4718	<div class="source">
				4719	<div class="source">
				4720	<pre>let $r1 := {"id": 1,
				4721	"project": "AsterixDB",
				4722	"address": {"city": "Irvine", "state": "CA"},
				4723	"related": ["Hivestrix", "Preglix", "Apache VXQuery"] }
				4724	return get-record-field-value($r1, "project")
				4725	</pre></div></div></li>
				4726
				4727	<li>
				4728	<p>The expected result is:</p>
				4729
				4730	<div class="source">
				4731	<div class="source">
				4732	<pre>"AsterixDB"
				4733	</pre></div></div></li>
				4734	</ul></div></div>
				4735	<div class="section">
				4736	<h2><a name="Other_Functions_Back_to_TOC"></a><a name="OtherFunctions" id="OtherFunctions">Other Functions</a> <font size="4"><a href="#toc">[Back to TOC]</a></font></h2>
				4737	<div class="section">
				4738	<h3><a name="create-uuid"></a>create-uuid</h3>
				4739
				4740	<ul>
				4741
				4742	<li>
				4743	<p>Syntax:</p>
				4744
				4745	<div class="source">
				4746	<div class="source">
				4747	<pre>create-uuid()
				4748	</pre></div></div></li>
				4749
				4750	<li>
				4751	<p>Generates a <tt>uuid</tt>.</p></li>
				4752
				4753	<li>Arguments:
				4754
				4755	<ul>
				4756
				4757	<li>none</li>
				4758	</ul></li>
				4759
				4760	<li>Return Value:
				4761
				4762	<ul>
				4763
				4764	<li>A generated <tt>uuid</tt>.</li>
				4765	</ul></li>
				4766	</ul></div>
				4767	<div class="section">
				4768	<h3><a name="is-null"></a>is-null</h3>
				4769
				4770	<ul>
				4771
				4772	<li>
				4773	<p>Syntax:</p>
				4774
				4775	<div class="source">
				4776	<div class="source">
				4777	<pre>is-null(var)
				4778	</pre></div></div></li>
				4779
				4780	<li>
				4781	<p>Checks whether the given variable is a <tt>null</tt> value.</p></li>
				4782
				4783	<li>Arguments:
				4784
				4785	<ul>
				4786
				4787	<li><tt>var</tt> : A variable (any type is allowed).</li>
				4788	</ul></li>
				4789
				4790	<li>Return Value:
				4791
				4792	<ul>
				4793
				4794	<li>A <tt>boolean</tt> on whether the variable is a <tt>null</tt> or not.</li>
				4795	</ul></li>
				4796
				4797	<li>
				4798	<p>Example:</p>
				4799
				4800	<div class="source">
				4801	<div class="source">
				4802	<pre>for $m in ['hello', 'world', null]
				4803	where not(is-null($m))
				4804	return $m
				4805	</pre></div></div></li>
				4806	</ul>
				4807
				4808	<ul>
				4809
				4810	<li>
				4811	<p>The expected result is:</p>
				4812
				4813	<div class="source">
				4814	<div class="source">
				4815	<pre>"hello"
				4816	"world"
				4817	</pre></div></div></li>
				4818	</ul></div>
				4819	<div class="section">
				4820	<h3><a name="is-system-null"></a>is-system-null</h3>
				4821
				4822	<ul>
				4823
				4824	<li>
				4825	<p>Syntax:</p>
				4826
				4827	<div class="source">
				4828	<div class="source">
				4829	<pre>is-system-null(var)
				4830	</pre></div></div></li>
				4831
				4832	<li>
				4833	<p>Checks whether the given variable is a <tt>system null</tt> value.</p></li>
				4834
				4835	<li>Arguments:
				4836
				4837	<ul>
				4838
				4839	<li><tt>var</tt> : A variable (any type is allowed).</li>
				4840	</ul></li>
				4841
				4842	<li>Return Value:
				4843
				4844	<ul>
				4845
				4846	<li>A <tt>boolean</tt> on whether the variable is a <tt>system null</tt> or not.</li>
				4847	</ul></li>
				4848	</ul></div>
				4849	<div class="section">
				4850	<h3><a name="len"></a>len</h3>
				4851
				4852	<ul>
				4853
				4854	<li>
				4855	<p>Syntax:</p>
				4856	<p>len(list_expression)</p></li>
				4857
				4858	<li>
				4859	<p>Returns the length of the list list_expression.</p></li>
				4860
				4861	<li>Arguments:
				4862
				4863	<ul>
				4864
				4865	<li><tt>list_expression</tt> : An <tt>OrderedList</tt>, <tt>UnorderedList</tt> or <tt>null</tt>, represents the list need to be checked.</li>
				4866	</ul></li>
				4867
				4868	<li>Return Value:
				4869
				4870	<ul>
				4871
				4872	<li>An <tt>Int32</tt> that represents the length of list_expression.</li>
				4873	</ul></li>
				4874
				4875	<li>
				4876	<p>Example:</p>
				4877
				4878	<div class="source">
				4879	<div class="source">
				4880	<pre>use dataverse TinySocial;
				4881
				4882	let $l := ["ASTERIX", "Hyracks"]
				4883	return len($l)
				4884	</pre></div></div></li>
				4885	</ul>
				4886
				4887	<ul>
				4888
				4889	<li>
				4890	<p>The expected result is:</p>
				4891
				4892	<div class="source">
				4893	<div class="source">
				4894	<pre>2
				4895	</pre></div></div></li>
				4896	</ul></div>
				4897	<div class="section">
				4898	<h3><a name="not"></a>not</h3>
				4899
				4900	<ul>
				4901
				4902	<li>
				4903	<p>Syntax:</p>
				4904
				4905	<div class="source">
				4906	<div class="source">
				4907	<pre>not(var)
				4908	</pre></div></div></li>
				4909
				4910	<li>
				4911	<p>Inverts a <tt>boolean</tt> value</p></li>
				4912
				4913	<li>Arguments:
				4914
				4915	<ul>
				4916
				4917	<li><tt>var</tt> : A <tt>boolean</tt> (or <tt>null</tt>)</li>
				4918	</ul></li>
				4919
				4920	<li>Return Value:
				4921
				4922	<ul>
				4923
				4924	<li>A <tt>boolean</tt>, the inverse of <tt>var</tt>. returns <tt>null</tt> if <tt>var</tt> is null</li>
				4925	</ul></li>
				4926
				4927	<li>
				4928	<p>Example:</p>
				4929
				4930	<div class="source">
				4931	<div class="source">
				4932	<pre>for $m in ['hello', 'world', null]
				4933	where not(is-null($m))
				4934	return $m
				4935	</pre></div></div></li>
				4936
				4937	<li>
				4938	<p>The expected result is:</p>
				4939
				4940	<div class="source">
				4941	<div class="source">
				4942	<pre>"hello"
				4943	"world"
				4944	</pre></div></div></li>
				4945	</ul></div>
				4946	<div class="section">
				4947	<h3><a name="range"></a>range</h3>
				4948
				4949	<ul>
				4950
				4951	<li>
				4952	<p>Syntax:</p>
				4953
				4954	<div class="source">
				4955	<div class="source">
				4956	<pre>range(start_numeric_expression, end_numeric_expression)
				4957	</pre></div></div></li>
				4958
				4959	<li>
				4960	<p>Generates a series of <tt>int64</tt> values based start the <tt>start_numeric_expression</tt> until the <tt>end_numeric_expression</tt>. The <tt>range</tt> fucntion must be used list argument of a <tt>for</tt> expression.</p></li>
				4961
				4962	<li>Arguments:</li>
				4963
				4964	<li><tt>start_numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt> value representing the start value.</li>
				4965
				4966	<li><tt>end_numeric_expression</tt>: A <tt>int8</tt>/<tt>int16</tt>/<tt>int32</tt>/<tt>int64</tt> value representing the max final value.</li>
				4967
				4968	<li>Return Value:
				4969
				4970	<ul>
				4971
				4972	<li>A generated <tt>uuid</tt>.</li>
				4973	</ul></li>
				4974
				4975	<li>
				4976	<p>Example:</p>
				4977
				4978	<div class="source">
				4979	<div class="source">
				4980	<pre>for $i in range(0, 3)
				4981	return $i;
				4982	</pre></div></div></li>
				4983
				4984	<li>
				4985	<p>The expected result is:</p>
				4986
				4987	<div class="source">
				4988	<div class="source">
				4989	<pre>[ 0
				4990	, 1
				4991	, 2
				4992	, 3
				4993	]
				4994	</pre></div></div></li>
				4995	</ul></div>
				4996	<div class="section">
				4997	<h3><a name="switch-case"></a>switch-case</h3>
				4998
				4999	<ul>
				5000
				5001	<li>
				5002	<p>Syntax:</p>
				5003
				5004	<div class="source">
				5005	<div class="source">
				5006	<pre>switch-case(condition,
				5007	case1, case1-result,
				5008	case2, case2-result,
				5009	...,
				5010	default, default-result
				5011	)
				5012	</pre></div></div></li>
				5013
				5014	<li>
				5015	<p>Switches amongst a sequence of cases and returns the result of the first matching case. If no match is found, the result of the default case is returned.</p></li>
				5016
				5017	<li>Arguments:
				5018
				5019	<ul>
				5020
				5021	<li><tt>condition</tt>: A variable (any type is allowed).</li>
				5022
				5023	<li><tt>caseI/default</tt>: A variable (any type is allowed).</li>
				5024
				5025	<li><tt>caseI/default-result</tt>: A variable (any type is allowed).</li>
				5026	</ul></li>
				5027
				5028	<li>Return Value:
				5029
				5030	<ul>
				5031
				5032	<li>Returns <tt>caseI-result</tt> if <tt>condition</tt> matches <tt>caseI</tt>, otherwise <tt>default-result</tt>.</li>
				5033	</ul></li>
				5034
				5035	<li>
				5036	<p>Example 1:</p>
				5037
				5038	<div class="source">
				5039	<div class="source">
				5040	<pre>switch-case("a",
				5041	"a", 0,
				5042	"x", 1,
				5043	"y", 2,
				5044	"z", 3
				5045	)
				5046	</pre></div></div></li>
				5047	</ul>
				5048
				5049	<ul>
				5050
				5051	<li>
				5052	<p>The expected result is:</p>
				5053
				5054	<div class="source">
				5055	<div class="source">
				5056	<pre>0
				5057	</pre></div></div></li>
				5058
				5059	<li>
				5060	<p>Example 2:</p>
				5061
				5062	<div class="source">
				5063	<div class="source">
				5064	<pre>switch-case("a",
				5065	"x", 1,
				5066	"y", 2,
				5067	"z", 3
				5068	)
				5069	</pre></div></div></li>
				5070
				5071	<li>
				5072	<p>The expected result is:</p>
				5073
				5074	<div class="source">
				5075	<div class="source">
				5076	<pre>3
				5077	</pre></div></div></li>
				5078	</ul></div></div>
				5079	</div>
				5080	</div>
				5081	</div>
				5082
				5083	<hr/>
				5084
				5085	<footer>
				5086	<div class="container-fluid">
				5087	<div class="row span12">Copyright © 2015
				5088	<a href="http://www.apache.org/">The Apache Software Foundation</a>.
				5089	All Rights Reserved.
				5090
				5091	</div>
				5092
				5093	<?xml version="1.0" encoding="UTF-8"?>
				5094	<div class="row-fluid">Apache AsterixDB, AsterixDB, Apache, the Apache
				5095	feather logo, and the Apache AsterixDB project logo are either
				5096	registered trademarks or trademarks of The Apache Software
				5097	Foundation in the United States and other countries.
				5098	All other marks mentioned may be trademarks or registered
				5099	trademarks of their respective owners.</div>
				5100
				5101
				5102	</div>
				5103	</footer>
				5104	</body>
				5105	</html>