Fixed issue with test metadata/queries/custord_q5.aql.

git-svn-id: https://asterixdb.googlecode.com/svn/branches/asterix_stabilization@198 eaa15691-b419-025a-1212-ee371bd00084
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/DdlTranslator.java b/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/DdlTranslator.java
index f3dc2d4..32b5058 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/DdlTranslator.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/DdlTranslator.java
@@ -155,10 +155,14 @@
                     IDatasetDetails datasetDetails = null;
                     Dataset ds = MetadataManager.INSTANCE.getDataset(mdTxnCtx, compiledDeclarations.getDataverseName(),
                             datasetName);
-                    if (ds != null && !dd.getIfNotExists()) {
-                        throw new AlgebricksException("A dataset with this name " + datasetName
-                                + " already exists.");
-                    } 
+                    if (ds != null) {
+                        if (dd.getIfNotExists()) {
+                            continue;                            
+                        } else {
+                            throw new AlgebricksException("A dataset with this name " + datasetName
+                                    + " already exists.");
+                        }
+                    }
                     itemTypeName = dd.getItemTypeName().getValue();
                     Datatype dt = MetadataManager.INSTANCE.getDatatype(mdTxnCtx,
                             compiledDeclarations.getDataverseName(), itemTypeName);