fixed #228

Author: wumpz

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

@@ -2119,10 +2119,11 @@ JsonExpression JsonExpression() : {
 IntervalExpression IntervalExpression() : {
 	IntervalExpression interval = new IntervalExpression();
 	Token token;
+	boolean signed = false;
 }
 {
-	<K_INTERVAL> (token=<S_LONG> | token=<S_DOUBLE> | token=<S_CHAR_LITERAL>) 
-    { interval.setParameter(token.image); }
+	<K_INTERVAL> ["-" {signed=true;}] (token=<S_LONG> | token=<S_DOUBLE> | token=<S_CHAR_LITERAL>) 
+    { interval.setParameter((signed?"-":"") + token.image); }
     [ LOOKAHEAD(2) token = <S_IDENTIFIER> { interval.setIntervalType(token.image); } ]
 	{
 		return interval;

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

@@ -1609,6 +1609,11 @@ public void testInterval4() throws JSQLParserException {
         String stmt = "SELECT '2008-12-31 23:59:59' + INTERVAL 1 SECOND";
         assertSqlCanBeParsedAndDeparsed(stmt);
     }
+    
+    public void testInterval5_Issue228() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT ADDDATE(timeColumn1, INTERVAL 420 MINUTES) AS timeColumn1 FROM tbl");
+        assertSqlCanBeParsedAndDeparsed("SELECT ADDDATE(timeColumn1, INTERVAL -420 MINUTES) AS timeColumn1 FROM tbl");
+    }
 
     public void testMultiValueIn() throws JSQLParserException {
         String stmt = "SELECT * FROM mytable WHERE (a, b, c) IN (SELECT a, b, c FROM mytable2)";