SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 1)
    WithElement (children 1)
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 1)
         ExpressionList (children 2)
          Function CAST (alias c) (children 1)
           ExpressionList (children 2)
            Literal \'key\'
            Literal \'Varchar(255)\'
          Function CAST (alias s) (children 1)
           ExpressionList (children 2)
            Literal \'x\'
            Literal \'Varchar(255)\'
   ExpressionList (children 2)
    Identifier r1
    Identifier c (alias r2)
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 2)
           Identifier t (alias s)
           Identifier c (alias r1)
          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 2)
                  Function CAST (alias t) (children 1)
                   ExpressionList (children 2)
                    Literal \'y\'
                    Literal \'Varchar(255)\'
                  Function CAST (alias s) (children 1)
                   ExpressionList (children 2)
                    Literal \'x\'
                    Literal \'Varchar(255)\'
           TablesInSelectQueryElement (children 2)
            TableExpression (children 1)
             TableIdentifier d
            TableJoin (children 1)
             ExpressionList (children 1)
              Identifier s
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier d
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier s
   Set
