feat: link all Expression AST Nodes

- fixes #1339

Signed-off-by: Andreas Reichel <andreas@manticore-projects.com>

Author: manticore-projects

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

@@ -4412,12 +4412,14 @@ First First():
 
 Expression Expression() #Expression :
 {
-    Expression retval = null;
+    Expression expression = null;
 }
 {
-    retval=XorExpression()
-
-    { return retval; }
+    expression=XorExpression()
+    {
+        linkAST(expression,jjtThis);
+        return expression;
+    }
 }
 
 Expression XorExpression():
@@ -4613,7 +4615,6 @@ Expression SQLCondition():
     | left = SimpleExpression() { result = left; }
         [
             LOOKAHEAD(2) (
-                (
                 LOOKAHEAD(ExcludesExpression()) result=ExcludesExpression(left)
                 |
                 LOOKAHEAD(IncludesExpression()) result=IncludesExpression(left)
@@ -4633,7 +4634,6 @@ Expression SQLCondition():
                 LOOKAHEAD(IsDistinctExpression()) result=IsDistinctExpression(left)
                 |
                 result=SimilarToExpression(left)
-                )
             )
         ]
     )

src/test/java/net/sf/jsqlparser/parser/ASTNodeAccessImplTest.java

@@ -11,9 +11,11 @@
 
 import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.expression.AnalyticExpression;
+import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.statement.select.PlainSelect;
 import net.sf.jsqlparser.statement.select.Select;
 import net.sf.jsqlparser.statement.select.SelectItem;
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -33,4 +35,25 @@ void testGetParent() throws JSQLParserException {
         assertInstanceOf(SelectItem.class, expression.getParent());
         assertEquals(select, expression.getParent(Select.class));
     }
+
+    @Test
+    void testGetWherePositionIssue1339() throws JSQLParserException {
+        // WHERE expression at line 4 column 7
+        String sqlStr = "select listagg(sellerid)\n"
+                + "within group (order by sellerid)\n"
+                + "over() AS list from winsales\n"
+                + "WHERE a=b\n"
+                + "ORDER BY 1;";
+        PlainSelect select = (PlainSelect) CCJSqlParserUtil.parse(sqlStr);
+        Expression whereExpression = select.getWhere();
+
+        final SimpleNode node = whereExpression.getASTNode();
+        if (node != null) {
+            Token token = node.jjtGetFirstToken();
+            Assertions.assertEquals(4, token.beginLine);
+            Assertions.assertEquals(7, token.beginColumn);
+        } else {
+            throw new RuntimeException("Node not found.");
+        }
+    }
 }