fixes #91

README.md

@@ -32,6 +32,12 @@ Also I would like to know about needed examples or documentation stuff.
 
 ## Extensions in the latest SNAPSHOT version 0.9.2
 
+* support for within group expressions, e.g. oracls LISTAGG function
+
+```sql
+SELECT LISTAGG(col1, '##') WITHIN GROUP (ORDER BY col1) FROM table1
+```
+
 * support for inner with statements 
 
 ```sql

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitor.java

@@ -136,6 +136,8 @@ public interface ExpressionVisitor {
 	void visit(Modulo modulo);
 
 	void visit(AnalyticExpression aexpr);
+
+    void visit(WithinGroupExpression wgexpr);
 
 	void visit(ExtractExpression eexpr);
 

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitorAdapter.java

@@ -312,4 +312,12 @@ public void visit(JsonExpression jsonExpr) {
 	public void visit(RegExpMySQLOperator expr) {
 		visitBinaryExpression(expr);	
 	}
+
+    @Override
+    public void visit(WithinGroupExpression wgexpr) {
+        wgexpr.getExprList().accept(this);
+        for (OrderByElement element : wgexpr.getOrderByElements()) {
+            element.getExpression().accept(this);
+        }
+    }
 }

src/main/java/net/sf/jsqlparser/expression/WithinGroupExpression.java

@@ -0,0 +1,90 @@
+/*
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2015 JSQLParser
+ * %%
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 2.1 of the
+ * License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Lesser Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Lesser Public
+ * License along with this program.  If not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ * #L%
+ */
+package net.sf.jsqlparser.expression;
+
+import java.util.List;
+import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
+import net.sf.jsqlparser.statement.select.OrderByElement;
+
+/**
+ *
+ * @author toben
+ */
+public class WithinGroupExpression implements Expression {
+
+    private String name;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    private List<OrderByElement> orderByElements;
+
+    public List<OrderByElement> getOrderByElements() {
+        return orderByElements;
+    }
+
+    public void setOrderByElements(List<OrderByElement> orderByElements) {
+        this.orderByElements = orderByElements;
+    }
+
+    private ExpressionList exprList;
+
+    public ExpressionList getExprList() {
+        return exprList;
+    }
+
+    public void setExprList(ExpressionList exprList) {
+        this.exprList = exprList;
+    }
+
+    @Override
+    public void accept(ExpressionVisitor visitor) {
+        visitor.visit(this);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder b = new StringBuilder();
+
+        b.append(name);
+        b.append(exprList.toString());
+        b.append(" WITHIN GROUP (");
+
+        b.append("ORDER BY ");
+        for (int i = 0; i < orderByElements.size(); i++) {
+            if (i > 0) {
+                b.append(", ");
+            }
+            b.append(orderByElements.get(i).toString());
+        }
+
+        b.append(")");
+
+        return b.toString();
+    }
+
+}

src/main/java/net/sf/jsqlparser/util/TablesNamesFinder.java

@@ -498,4 +498,8 @@ public void visit(AllTableColumns allTableColumns) {
     public void visit(SelectExpressionItem item) {
         item.getExpression().accept(this);
     }
+
+    @Override
+    public void visit(WithinGroupExpression wgexpr) {
+    }
 }

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

@@ -515,4 +515,9 @@ public void visit(JsonExpression jsonExpr) {
         buffer.append(jsonExpr.toString());
     }
 
+    @Override
+    public void visit(WithinGroupExpression wgexpr) {
+        buffer.append(wgexpr.toString());
+    }
+
 }

src/main/javacc/net/sf/jsqlparser/parser/JSqlParserCC.jj

@@ -206,6 +206,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_ONLY:"ONLY">
 |   <K_COMMIT:"COMMIT">
 |   <K_UNIQUE:"UNIQUE">
+|   <K_WITHIN:"WITHIN">
 }
 
 TOKEN : /* Numeric Constants */
@@ -1733,6 +1734,8 @@ Expression PrimaryExpression():
 
 	| LOOKAHEAD(AnalyticExpression()) retval=AnalyticExpression()
 
+    | LOOKAHEAD(WithinGroupExpression()) retval=WithinGroupExpression()
+
 	| LOOKAHEAD(ExtractExpression()) retval=ExtractExpression()
 
     | LOOKAHEAD([sign="+" | sign="-"] JsonExpression()) [sign="+" | sign="-"] retval=JsonExpression()
@@ -1814,6 +1817,26 @@ IntervalExpression IntervalExpression() : {
 	}
 }
 
+WithinGroupExpression WithinGroupExpression() :
+{
+    Token token = null;
+    List<OrderByElement> orderByElements = null;
+    WithinGroupExpression result = new WithinGroupExpression();
+    ExpressionList exprList;
+}
+{
+    token = <S_IDENTIFIER> "(" exprList = SimpleExpressionList() ")" 
+      <K_WITHIN> <K_GROUP>
+    "(" orderByElements = OrderByElements() ")"
+
+    { 
+        result.setName(token.image);
+        result.setExprList(exprList);
+        result.setOrderByElements(orderByElements);
+        return result; 
+    }
+}
+
 AnalyticExpression AnalyticExpression() :
 {
 	AnalyticExpression retval = new AnalyticExpression();

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

@@ -1649,4 +1649,8 @@ public void testSelectOracleColl() throws JSQLParserException {
     public void testSelectInnerWith() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("SELECT * FROM (WITH actor AS (SELECT 'a' aid FROM DUAL) SELECT aid FROM actor)");
     }
+
+    public void testSelectWithinGroup() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT LISTAGG(col1, '##') WITHIN GROUP (ORDER BY col1) FROM table1");
+    }
 }