TEIID-4157 allowing the translator to support nested set ops

teiid · Apr 21, 2016 · adf3ce0 · adf3ce0
1 parent 7ec4035
commit adf3ce0
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Showing 3 changed files with 56 additions and 16 deletions.
diff --git a/api/src/main/java/org/teiid/language/visitor/SQLStringVisitor.java b/api/src/main/java/org/teiid/language/visitor/SQLStringVisitor.java
@@ -916,10 +916,7 @@ protected boolean useParensForSetQueries() {
     }
 
     protected void appendSetQuery(SetQuery parent, QueryExpression obj, boolean right) {
-        if((!(obj instanceof SetQuery) && useParensForSetQueries()) 
-        		|| (!useSelectLimit() && (obj.getLimit() != null || obj.getOrderBy() != null)) || (right && ((obj instanceof SetQuery 
-        				&& ((parent.isAll() && !((SetQuery)obj).isAll()) 
-        						|| parent.getOperation() != ((SetQuery)obj).getOperation())) || obj.getLimit() != null || obj.getOrderBy() != null))) {
+        if(shouldNestSetChild(parent, obj, right)) {
             buffer.append(Tokens.LPAREN);
             append(obj);
             buffer.append(Tokens.RPAREN);
@@ -930,6 +927,14 @@ protected void appendSetQuery(SetQuery parent, QueryExpression obj, boolean righ
             append(obj);
         }
     }
+
+	protected boolean shouldNestSetChild(SetQuery parent, QueryExpression obj,
+			boolean right) {
+		return (!(obj instanceof SetQuery) && useParensForSetQueries()) 
+        		|| (!useSelectLimit() && (obj.getLimit() != null || obj.getOrderBy() != null)) || (right && ((obj instanceof SetQuery 
+        				&& ((parent.isAll() && !((SetQuery)obj).isAll()) 
+        						|| parent.getOperation() != ((SetQuery)obj).getOperation())) || obj.getLimit() != null || obj.getOrderBy() != null));
+	}
 
     @Override
     public void visit(With obj) {

diff --git a/...ors/translator-hive/src/main/java/org/teiid/translator/hive/HiveSQLConversionVisitor.java b/...ors/translator-hive/src/main/java/org/teiid/translator/hive/HiveSQLConversionVisitor.java
@@ -151,11 +151,13 @@ private void addColumn(DerivedColumn dc) {
 
     @Override
     public void visit(SetQuery obj) {
+    	//TODO: with hive 1.2, this handling is not necessary
+    	//even with hive 0.13 it's only partially necessary - for distinct
     	if (obj.getWith() != null) {
     		append(obj.getWith());
     	}
 
-    	Select select =  (Select)obj.getLeftQuery();
+    	Select select =  obj.getProjectedQuery();
     	buffer.append(SELECT).append(Tokens.SPACE);
     	if(!obj.isAll()) {
     		buffer.append(DISTINCT).append(Tokens.SPACE);
@@ -164,20 +166,13 @@ public void visit(SetQuery obj) {
     	buffer.append(Tokens.SPACE);
     	buffer.append(FROM).append(Tokens.SPACE);
     	buffer.append(Tokens.LPAREN);
-    	 
-        appendSetQuery(obj, obj.getLeftQuery(), false);
+
+    	appendSetChild(obj, obj.getLeftQuery(), false);
 
-        buffer.append(Tokens.SPACE);
+        appendSetOp(obj);
 
-        appendSetOperation(obj.getOperation());
-
-        // UNION "ALL" always
-        buffer.append(Tokens.SPACE);
-        buffer.append(ALL);                
-        buffer.append(Tokens.SPACE);
+        appendSetChild(obj, obj.getRightQuery(), true);
 
-        appendSetQuery(obj, obj.getRightQuery(), true);
-
         OrderBy orderBy = obj.getOrderBy();
         if(orderBy != null) {
             buffer.append(Tokens.SPACE);
@@ -193,6 +188,32 @@ public void visit(SetQuery obj) {
         buffer.append(Tokens.SPACE);
         buffer.append("X__"); //$NON-NLS-1$
     }
+
+	private void appendSetOp(SetQuery obj) {
+		buffer.append(Tokens.SPACE);
+
+        appendSetOperation(obj.getOperation());
+
+        // UNION "ALL" always
+        buffer.append(Tokens.SPACE);
+        buffer.append(ALL);                
+        buffer.append(Tokens.SPACE);
+	}
+
+	private void appendSetChild(SetQuery obj, QueryExpression child, boolean right) {
+		if (child instanceof Select || shouldNestSetChild(obj, child, right)) {
+    		appendSetQuery(obj, child, right);
+    	} else {
+    		//non-nested set op
+    		SetQuery setQuery = (SetQuery)child;
+
+            append(setQuery.getLeftQuery());
+
+            appendSetOp(setQuery);
+
+            appendSetChild(setQuery, setQuery.getRightQuery(), true);
+    	}
+	}
 
     @Override
     public void visit(Select obj) {

diff --git a/...ors/translator-hive/src/test/java/org/teiid/translator/hive/TestHiveExecutionFactory.java b/...ors/translator-hive/src/test/java/org/teiid/translator/hive/TestHiveExecutionFactory.java
@@ -142,6 +142,20 @@ public void testUnionAllRewrite() throws Exception {
         helpTestVisitor(bqt, input, output);    	
     }
 
+    @Test
+    public void testUnionAllRewriteNested() throws Exception {
+        String input = "SELECT intkey, stringkey FROM BQT1.SmallA union all SELECT intkey, stringkey FROM BQT1.Smallb union all SELECT intkey, stringkey FROM BQT1.Smallb"; 
+        String output = "SELECT intkey, stringkey FROM (SELECT SmallA.IntKey, SmallA.StringKey FROM SmallA UNION ALL SELECT SmallB.IntKey, SmallB.StringKey FROM SmallB UNION ALL SELECT SmallB.IntKey, SmallB.StringKey FROM SmallB) X__"; 
+        helpTestVisitor(bqt, input, output);    	
+    }
+
+    @Test
+    public void testUnionAllRewriteNested1() throws Exception {
+        String input = "SELECT intkey, stringkey FROM BQT1.SmallA union all (SELECT intkey, stringkey FROM BQT1.Smallb union SELECT intkey, stringkey FROM BQT1.Smallb)"; 
+        String output = "SELECT intkey, stringkey FROM (SELECT SmallA.IntKey, SmallA.StringKey FROM SmallA UNION ALL (SELECT DISTINCT intkey, stringkey FROM (SELECT SmallB.IntKey, SmallB.StringKey FROM SmallB UNION ALL SELECT SmallB.IntKey, SmallB.StringKey FROM SmallB) X__)) X__"; 
+        helpTestVisitor(bqt, input, output);    	
+    }
+
     @Test
     public void testUnionAllExprRewrite() throws Exception {
         String input = "SELECT count(*) as key, stringkey FROM BQT1.SmallA union all SELECT intkey, stringkey FROM BQT1.Smallb";