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いくつかの（レガシー）SQLコードをサポートする関数を作成しようとしています。関数はクエリの一部として使用されます。

SELECT
  q.*,
  fn_qncatxml(q.number, q.version) AS categories --XML aggregated category hierarchy
FROM
  [dbo].[qn] q

残念ながら、SQL Serverには関数内のCTE式に関する既知の問題があるため、次のアプローチは機能しません（WITHソリューションの前のセミコロン）。残念ながら、このソリューションを次のようなスカラーを返す関数に適用する方法がわかりません。

CREATE FUNCTION [dbo].[fn_qncatxml](@qnnumber INT, @qnversion INT)
RETURNS XML
WITH RETURNS NULL ON NULL INPUT
BEGIN
  RETURN
  (
    WITH [categories] AS
    (
      SELECT [qn].[number], [qn].[version], [cat].[catnumber], [qncat].[itemnumber], [cat].[parent], [cat].[description], 0 AS [distance]
      FROM [qn]
      LEFT JOIN [qncat] ON [qncat].[qnnumber] = [qn].[number] AND [qncat].[qnversion] = [qn].[version]
      LEFT JOIN [cat] ON [cat].[catnumber] = [qncat].[catnumber] AND [cat].[status] = '1'
      WHERE [qn].[number] = @qnnumber AND [qn].[version] = @qnversion

      UNION ALL

      SELECT [categories].[number], [categories].[version], [cat].[catnumber], [categories].[itemnumber], [cat].[parent], [cat].[description], [categories].[distance] + 1 AS [distance]
      FROM [categories]
      JOIN [cat] ON [cat].[catnumber] = [categories].[parent]
      WHERE
        [cat].[status] = '1'
    )
    SELECT DISTINCT * FROM [categories] FOR XML PATH('')
  )
END

WITHとFORXMLPATH（''）の間の部分を取り除き、いくつかの有効な引数を指定してこのブロックを実行すると、完全に機能します。

このCTE関数構文を私のシナリオで機能させる方法の手がかりはありますか？

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CREATE FUNCTION [dbo].[fn_qncatxml](@qnnumber INT, @qnversion INT)
RETURNS XML
WITH RETURNS NULL ON NULL INPUT
BEGIN
  DECLARE @Ret xml;

  WITH [categories] AS
  (
    SELECT [qn].[number], [qn].[version], [cat].[catnumber], [qncat].[itemnumber], [cat].[parent], [cat].[description], 0 AS [distance]
    FROM [qn]
    LEFT JOIN [qncat] ON [qncat].[qnnumber] = [qn].[number] AND [qncat].[qnversion] = [qn].[version]
    LEFT JOIN [cat] ON [cat].[catnumber] = [qncat].[catnumber] AND [cat].[status] = '1'
    WHERE [qn].[number] = @qnnumber AND [qn].[version] = @qnversion

    UNION ALL

    SELECT [categories].[number], [categories].[version], [cat].[catnumber], [categories].[itemnumber], [cat].[parent], [cat].[description], [categories].[distance] + 1 AS [distance]
    FROM [categories]
    JOIN [cat] ON [cat].[catnumber] = [categories].[parent]
    WHERE
      [cat].[status] = '1'
  )
  SELECT @Ret = (SELECT DISTINCT * FROM [categories] FOR XML PATH(''))

  RETURN @Ret
END
于 2011-07-14T13:48:50.250 に答える