SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 3) Identifier col1 Identifier col2 Function nullIf (children 1) ExpressionList (children 2) Identifier col1 Identifier col2 TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier test1_00395 ExpressionList (children 2) OrderByElement (children 1) Identifier col1 OrderByElement (children 1) Identifier col2