SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 2) QualifiedAsterisk (children 1) Identifier t1 QualifiedAsterisk (children 1) Identifier t2 TablesInSelectQuery (children 2) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier t1 TablesInSelectQueryElement (children 2) TableExpression (children 1) TableIdentifier t2 TableJoin (children 1) Function equals (children 1) ExpressionList (children 2) Identifier t1.y Identifier t2.y ExpressionList (children 1) OrderByElement (children 1) Identifier x