group_concat started

Author: wumpz

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

@@ -212,6 +212,8 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_RECURSIVE:"RECURSIVE">
 |   <K_OF:"OF">
 |   <K_KEEP:"KEEP">
+|   <K_GROUP_CONCAT:"GROUP_CONCAT">
+|   <K_SEPARATOR:"SEPARATOR">
 }
 
 TOKEN : /* Numeric Constants */
@@ -1782,6 +1784,8 @@ Expression PrimaryExpression():
 
 	| LOOKAHEAD(ExtractExpression()) retval=ExtractExpression()
 
+    | MySQLGroupConcat()
+
     | LOOKAHEAD([sign="+" | sign="-"] JsonExpression()) [sign="+" | sign="-"] retval=JsonExpression()
 
 	| LOOKAHEAD(["+" | "-"] Function())       [sign="+" | sign="-"] retval=Function()
@@ -2146,6 +2150,16 @@ Function Function():
     }
 }
 
+void MySQLGroupConcat():{}
+{
+    <K_GROUP_CONCAT> "(" 
+       [<K_DISTINCT>] SimpleExpressionList() 
+       OrderByElements()
+       [ <K_SEPARATOR> <S_CHAR_LITERAL> ]
+    ")"
+}
+
+
 SubSelect SubSelect():
 {
 	SelectBody selectBody = null;

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

@@ -1745,4 +1745,8 @@ public void testSelectKeep() throws JSQLParserException {
     public void testSelectKeepOver() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("SELECT MIN(salary) KEEP (DENSE_RANK FIRST ORDER BY commission_pct) OVER (PARTITION BY department_id ) \"Worst\" FROM employees ORDER BY department_id, salary");
     }
+    
+    public void testGroupConcat() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT student_name, GROUP_CONCAT(DISTINCT test_score ORDER BY test_score DESC SEPARATOR ' ') FROM student GROUP BY student_name");
+    }
 }