fixes #17

Author: wumpz

README.md

@@ -59,6 +59,7 @@ Also I would like to know about needed examples or documentation stuff.
 
 ## Extensions in the latest SNAPSHOT version 2.0
 
+* support for **GROUPING SETS**
 * first support for db date arithmentic
 * support for chained functions
 * first support for **FOR XML PATH**

src/main/java/net/sf/jsqlparser/statement/select/GroupByElement.java

@@ -12,10 +12,12 @@
 import java.util.ArrayList;
 import java.util.List;
 import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
 
 public class GroupByElement {
 
     private List<Expression> groupByExpressions = new ArrayList<>();
+    private List groupingSets = new ArrayList();
 
     public void accept(GroupByVisitor groupByVisitor) {
         groupByVisitor.visit(this);
@@ -33,12 +35,47 @@ public void addGroupByExpression(Expression groupByExpression) {
         groupByExpressions.add(groupByExpression);
     }
 
+    public List getGroupingSets() {
+        return groupingSets;
+    }
+
+    public void setGroupingSets(List groupingSets) {
+        this.groupingSets = groupingSets;
+    }
+
+    public void addGroupingSet(Expression expr) {
+        this.groupingSets.add(expr);
+    }
+
+    public void addGroupingSet(ExpressionList list) {
+        this.groupingSets.add(list);
+    }
+
     @Override
     public String toString() {
         StringBuilder b = new StringBuilder();
         b.append("GROUP BY ");
 
-        b.append(PlainSelect.getStringList(groupByExpressions));
+        if (groupByExpressions.size() > 0) {
+            b.append(PlainSelect.getStringList(groupByExpressions));
+        } else if (groupingSets.size() > 0) {
+            b.append("GROUPING SETS (");
+            boolean first = true;
+            for (Object o : groupingSets) {
+                if (first) {
+                    first = false;
+                } else {
+                    b.append(", ");
+                }
+                if (o instanceof Expression) {
+                    b.append(o.toString());
+                } else if (o instanceof ExpressionList) {
+                    ExpressionList list = (ExpressionList) o;
+                    b.append(list.getExpressions() == null ? "()" : list.toString());
+                }
+            }
+            b.append(")");
+        }
 
         return b.toString();
     }

src/main/java/net/sf/jsqlparser/util/deparser/GroupByDeParser.java

@@ -12,6 +12,7 @@
 import java.util.Iterator;
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.expression.ExpressionVisitor;
+import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
 import net.sf.jsqlparser.statement.select.GroupByElement;
 
 public class GroupByDeParser {
@@ -35,6 +36,24 @@ public void deParse(GroupByElement groupBy) {
                 buffer.append(", ");
             }
         }
+        if (groupBy.getGroupingSets().size() > 0) {
+            buffer.append("GROUPING SETS (");
+            boolean first = true;
+            for (Object o : groupBy.getGroupingSets()) {
+                if (first) {
+                    first = false;
+                } else {
+                    buffer.append(", ");
+                }
+                if (o instanceof Expression) {
+                    buffer.append(o.toString());
+                } else if (o instanceof ExpressionList) {
+                    ExpressionList list = (ExpressionList) o;
+                    buffer.append(list.getExpressions() == null ? "()" : list.toString());
+                }
+            }
+            buffer.append(")");
+        }
     }
 
     void setExpressionVisitor(ExpressionVisitor expressionVisitor) {

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -173,6 +173,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_FULL:"FULL">
 |   <K_FULLTEXT:"FULLTEXT">
 |   <K_GROUP:"GROUP">
+|   <K_GROUPING:"GROUPING">
 |   <K_GROUP_CONCAT:"GROUP_CONCAT">
 |   <K_HAVING:"HAVING">
 |   <K_HIGH_PRIORITY : "HIGH_PRIORITY">
@@ -248,6 +249,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_SEMI : "SEMI">
 |   <K_SEPARATOR:"SEPARATOR">
 |   <K_SET:"SET">
+|   <K_SETS:"SETS">
 |   <K_SHOW : "SHOW">
 |   <K_SIBLINGS:"SIBLINGS">
 |   <K_SKIP: "SKIP">
@@ -1799,10 +1801,25 @@ GroupByElement GroupByColumnReferences():
 {
     Expression columnReference;
     GroupByElement groupBy = new GroupByElement();
+    Expression expr;
+    ExpressionList list;
 }
 {
-    <K_GROUP> <K_BY> columnReference=SimpleExpression() {groupBy.addGroupByExpression(columnReference); }
-    ("," columnReference=SimpleExpression()  {groupBy.addGroupByExpression(columnReference); } )*
+    <K_GROUP> <K_BY> 
+    (
+        columnReference=SimpleExpression() {groupBy.addGroupByExpression(columnReference); }
+        ("," columnReference=SimpleExpression()  {groupBy.addGroupByExpression(columnReference); } )*
+    |
+        <K_GROUPING> <K_SETS> "(" 
+            ( LOOKAHEAD(2) "(" ")" { groupBy.addGroupingSet(new ExpressionList()); }
+                | LOOKAHEAD(3) "(" list = SimpleExpressionList() ")" { groupBy.addGroupingSet(list); } 
+                | expr = SimpleExpression() { groupBy.addGroupingSet(expr); } )
+
+            ( "," ( LOOKAHEAD(2) "(" ")" { groupBy.addGroupingSet(new ExpressionList()); }
+                | LOOKAHEAD(3) "(" list = SimpleExpressionList() ")" { groupBy.addGroupingSet(list); } 
+                | expr = SimpleExpression() { groupBy.addGroupingSet(expr); } ) )*
+        ")" 
+    )
     {
         return groupBy;
     }

src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java

@@ -3595,17 +3595,17 @@ public void visit(PlainSelect plainSelect) {
     @Test
     public void testGroupingSets1() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("SELECT COL_1, COL_2, COL_3, COL_4, COL_5, COL_6 FROM TABLE_1 "
-                + "GROUP  BY "
-                + " GROUPING SETS( (COL_1, COL_2, COL_3, COL_4), (COL_5, COL_6))");
+                + "GROUP BY "
+                + "GROUPING SETS ((COL_1, COL_2, COL_3, COL_4), (COL_5, COL_6))");
     }
 
     @Test
     public void testGroupingSets2() throws JSQLParserException {
-        assertSqlCanBeParsedAndDeparsed("SELECT COL_1 FROM TABLE_1 GROUP  BY GROUPING SETS( COL_1 )");
+        assertSqlCanBeParsedAndDeparsed("SELECT COL_1 FROM TABLE_1 GROUP BY GROUPING SETS (COL_1)");
     }
 
     @Test
     public void testGroupingSets3() throws JSQLParserException {
-        assertSqlCanBeParsedAndDeparsed("SELECT COL_1 FROM TABLE_1 GROUP  BY GROUPING SETS( COL_1, () )");
+        assertSqlCanBeParsedAndDeparsed("SELECT COL_1 FROM TABLE_1 GROUP BY GROUPING SETS (COL_1, ())");
     }
 }