SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Asterisk TablesInSelectQuery (children 2) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier t1 TablesInSelectQueryElement (children 2) TableExpression (children 1) TableIdentifier rdb TableJoin (children 1) Function equals (children 1) ExpressionList (children 2) Identifier rdb.key Identifier t1.k