SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function ifNull (alias res) (children 1)
     ExpressionList (children 2)
      Literal UInt64_1
      Literal NULL
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier res