SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function CAST (children 1)
     ExpressionList (children 2)
      Literal UInt64_1
      Literal \'String\'
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t1) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal UInt64_1 (alias iid)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias t2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal \'1\' (alias sid)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier t2.sid
        Function CAST (children 1)
         ExpressionList (children 2)
          Identifier t1.iid
          Literal \'String\'