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這篇文章主要講解了“SQL Server 中怎么改寫內聯表值函數”，文中的講解內容簡單清晰，易于學習與理解，下面請大家跟著丸趣 TV 小編的思路慢慢深入，一起來研究和學習“SQL Server 中怎么改寫內聯表值函數”吧！
問題 SQL：
SELECT TOP 1001 ha.HuntApplicationID ,
ha.PartyNumber ,
mht.Name AS MasterHuntTypeName ,
htly.LicenseYear ,
lStatus.[Status] AS DrawTicketStatus ,
isnull(dbo.udf_GetHuntApplicationPartyCount(ha.HuntApplicationID), 0) AS MemberCount ,
count( won.DrawTicketLicenseID) AS DrawnMemberCount ,
won.drawticketid ,
dt.PreDrawNonResidentMemberCount AS NRMemberCount ,
dbo.udf_GetAvgPreferencePoints(dt.DrawTicketID) AS PreferencePointAverage ,
CASE
WHEN ha.Quantity 1 THEN NULL
ELSE dt.PreDrawRandomNumber
END AS PreDrawRandomNumber ,
dsm.Name AS DrawSelectionMethodName ,
dt.DrawnSequence ,
dt.PreferencePointRank ,
dt.DrawID ,
dt.RandomRank
FROM dbo.HuntApplication ha
JOIN dbo.HuntTypeLicenseYear htly ON ha.HuntTypeLicenseYearID = htly.HuntTypeLicenseYearID
JOIN dbo.MasterHuntType mht ON htly.MasterHuntTypeID = mht.MasterHuntTypeID
LEFT JOIN dbo.HuntApplicationLicense hal ON ha.HuntApplicationID = hal.HuntApplicationID
LEFT JOIN dbo.DrawTicket dt ON ha.HuntApplicationID = dt.HuntApplicationID
LEFT JOIN dbo.DrawTicketLicense won ON dt.DrawTicketID = won.DrawTicketID
AND won.WasDrawn = 1
LEFT JOIN dbo.DrawSelectionMethod dsm ON dt.DrawSelectionMethodID = dsm.DrawSelectionMethodID
LEFT JOIN dbo.StatusCode lStatus ON dt.StatusCodeID = lStatus.StatusCodeID
JOIN dbo.DrawTicketHuntChoice dthc ON dt.DrawTicketID = dthc.DrawTicketID
CROSS APPLY dbo.tvf_GetHuntApplicationPartyCount(ha.HuntApplicationID) hapc
CROSS APPLY dbo.tvf_GetAvgPreferencePoints(dt.DrawTicketID) app
WHERE 1 = 1
AND htly.MasterHuntTypeID = @iMasterHuntTypeID
AND htly.LicenseYear = @iLicenseYear
AND dt.StatusCodeID = @iDrawTicketStatusCodeID
AND dthc.WasDrawn = @iHuntChoiceWasDrawn
GROUP BY ha.HuntApplicationID,
ha.PartyNumber,
mht.[Name],
htly.LicenseYear,
lStatus.[Status],
isnull(dbo.udf_GetHuntApplicationPartyCount(ha.HuntApplicationID), 0),
won.DrawTicketID,
dt.PreDrawNonResidentMemberCount,
dbo.udf_GetAvgPreferencePoints(dt.DrawTicketID),
CASE
WHEN ha.Quantity 1 THEN NULL
ELSE dt.PreDrawRandomNumber
END,
dsm.[Name],
dt.DrawnSequence,
dt.PreferencePointRank,
dt.DrawID,
dt.RandomRank
ORDER BY htly.LicenseYear DESC,
mht.Name,
lStatus.[Status],
dt.DrawID,
PreferencePointAverage DESC,
PreDrawRandomNumber,
ha.PartyNumber靜態函數：
CREATE FUNCTION [dbo].[udf_GetAvgPreferencePoints]
(@DrawTicketID INT)
RETURNS NUMERIC (18, 3)
BEGIN
RETURN
SELECT TOP 1
CONVERT(DECIMAL, dt.PreDrawPreferencePointTotal) / NULLIF(CONVERT(DECIMAL, dt.PreDrawMemberCount),0)
FROM dbo.DrawTicket dt
WHERE dt.DrawTicketID = @DrawTicketID
END執行時間 40s
這是典型可以進行靜態函數改寫內聯表值函數的 sql：
改寫后：
SELECT TOP 1001 ha.HuntApplicationID ,
ha.PartyNumber ,
mht.Name AS MasterHuntTypeName ,
htly.LicenseYear ,
lStatus.[Status] AS DrawTicketStatus ,
--isnull(dbo.udf_GetHuntApplicationPartyCount(ha.HuntApplicationID), 0) AS MemberCount ,
isnull(hapc.MemberCount, 0) AS MemberCount,
count( won.DrawTicketLicenseID) AS DrawnMemberCount ,
won.drawticketid ,
dt.PreDrawNonResidentMemberCount AS NRMemberCount ,
--dbo.udf_GetAvgPreferencePoints(dt.DrawTicketID) AS PreferencePointAverage ,
app.PreferencePointAverage PreferencePointAverage,
CASE
WHEN ha.Quantity 1 THEN NULL
ELSE dt.PreDrawRandomNumber
END AS PreDrawRandomNumber ,
dsm.Name AS DrawSelectionMethodName ,
dt.DrawnSequence ,
dt.PreferencePointRank ,
dt.DrawID ,
dt.RandomRank
FROM dbo.HuntApplication ha
JOIN dbo.HuntTypeLicenseYear htly ON ha.HuntTypeLicenseYearID = htly.HuntTypeLicenseYearID
JOIN dbo.MasterHuntType mht ON htly.MasterHuntTypeID = mht.MasterHuntTypeID
LEFT JOIN dbo.HuntApplicationLicense hal ON ha.HuntApplicationID = hal.HuntApplicationID
LEFT JOIN dbo.DrawTicket dt ON ha.HuntApplicationID = dt.HuntApplicationID
LEFT JOIN dbo.DrawTicketLicense won ON dt.DrawTicketID = won.DrawTicketID
AND won.WasDrawn = 1
LEFT JOIN dbo.DrawSelectionMethod dsm ON dt.DrawSelectionMethodID = dsm.DrawSelectionMethodID
LEFT JOIN dbo.StatusCode lStatus ON dt.StatusCodeID = lStatus.StatusCodeID
JOIN dbo.DrawTicketHuntChoice dthc ON dt.DrawTicketID = dthc.DrawTicketID
CROSS APPLY dbo.tvf_GetHuntApplicationPartyCount(ha.HuntApplicationID) hapc
CROSS APPLY dbo.tvf_GetAvgPreferencePoints(dt.DrawTicketID) app
WHERE 1 = 1
AND htly.MasterHuntTypeID = @iMasterHuntTypeID
AND htly.LicenseYear = @iLicenseYear
AND dt.StatusCodeID = @iDrawTicketStatusCodeID
AND dthc.WasDrawn = @iHuntChoiceWasDrawn
GROUP BY ha.HuntApplicationID,
ha.PartyNumber,
mht.[Name],
htly.LicenseYear,
lStatus.[Status],
--isnull(dbo.udf_GetHuntApplicationPartyCount(ha.HuntApplicationID), 0),
isnull(hapc.MemberCount, 0),
won.DrawTicketID,
dt.PreDrawNonResidentMemberCount,
--dbo.udf_GetAvgPreferencePoints(dt.DrawTicketID),
app.PreferencePointAverage,
CASE
WHEN ha.Quantity 1 THEN NULL
ELSE dt.PreDrawRandomNumber
END,
dsm.[Name],
dt.DrawnSequence,
dt.PreferencePointRank,
dt.DrawID,
dt.RandomRank
ORDER BY htly.LicenseYear DESC,
mht.Name,
lStatus.[Status],
dt.DrawID,
PreferencePointAverage DESC,
PreDrawRandomNumber,
ha.PartyNumber對應的表值函數：
CREATE FUNCTION [dbo].[tvf_GetAvgPreferencePoints]
(@DrawTicketID INT)
RETURNS TABLE WITH SCHEMABINDING
RETURN
SELECT TOP 1
CONVERT(DECIMAL, dt.PreDrawPreferencePointTotal) / NULLIF(CONVERT(DECIMAL, dt.PreDrawMemberCount),0) as PreferencePointAverage
FROM dbo.DrawTicket dt
WHERE dt.DrawTicketID = @DrawTicketID
GO改寫后執行時間從 40s 降低到 16s，對于傾斜列的優化速度更為明顯
感謝各位的閱讀，以上就是“SQL Server 中怎么改寫內聯表值函數”的內容了，經過本文的學習后，相信大家對 SQL Server 中怎么改寫內聯表值函數這一問題有了更深刻的體會，具體使用情況還需要大家實踐驗證。這里是丸趣 TV，丸趣 TV 小編將為大家推送更多相關知識點的文章，歡迎關注！
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