SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 4) ExpressionList (children 1) Asterisk TablesInSelectQuery (children 2) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier t1 TablesInSelectQueryElement (children 2) TableExpression (children 1) TableIdentifier t2 TableJoin (children 1) Literal NULL ExpressionList (children 2) OrderByElement (children 1) Identifier t1.id OrderByElement (children 1) Identifier t2.id Set