SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 6)
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier x
    Identifier x
    Function isNull (children 1)
     ExpressionList (children 1)
      Identifier x
    Function if (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier x
        Literal UInt64_0
      Literal \'fail\'
      Literal \'ok\'
    Function if (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier x
        Literal UInt64_1
      Literal \'fail\'
      Literal \'ok\'
    Function if (children 1)
     ExpressionList (children 3)
      Function greaterOrEquals (children 1)
       ExpressionList (children 2)
        Identifier x
        Literal UInt64_0
      Literal \'fail\'
      Literal \'ok\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function CAST (alias x) (children 1)
            ExpressionList (children 2)
             Literal NULL
             Literal \'Nullable(UInt8)\'