SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 5)
    Identifier b_num
    Function isNull (children 1)
     ExpressionList (children 1)
      Identifier b_num
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier b_num
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier b_num
      Literal UInt64_0
    Function if (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier b_num
        Literal UInt64_0
      Literal \'fail\'
      Literal \'ok\'
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias x) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal UInt64_1 (alias k)
           Function toInt8 (alias a_num) (children 1)
            ExpressionList (children 1)
             Literal UInt64_1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias y) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal UInt64_2 (alias k)
           Function toInt8 (alias b_num) (children 1)
            ExpressionList (children 1)
             Literal UInt64_1
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier k