SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   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)
           Function CAST (alias key) (children 1)
            ExpressionList (children 2)
             Literal \'1\'
             Literal \'UInt32\'
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias t2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function CAST (alias key) (children 1)
            ExpressionList (children 2)
             Literal NULL
             Literal \'Nullable(UInt32)\'
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier key
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier key
