SQLServer中怎么改写内联表值函数
这篇文章主要讲解了“SQL Server中怎么改写内联表值函数”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“SQL Server中怎么改写内联表值函数”吧！
创新互联建站坚持“要么做到，要么别承诺”的工作理念，服务领域包括：网站设计制作、成都网站制作、企业官网、英文网站、手机端网站、网站推广等服务，满足客户于互联网时代的大渡口网站设计、移动媒体设计的需求，帮助企业找到有效的互联网解决方案。努力成为您成熟可靠的网络建设合作伙伴！
问题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
静态函数：
CREATE FUNCTION [dbo].[udf_GetAvgPreferencePoints] (@DrawTicketID INT) RETURNS NUMERIC (18, 3) AS BEGIN RETURN ( SELECT TOP 1 CONVERT(DECIMAL, dt.PreDrawPreferencePointTotal) / NULLIF(CONVERT(DECIMAL, dt.PreDrawMemberCount),0) FROM dbo.DrawTicket dt WHERE dt.DrawTicketID = @DrawTicketID ) END
执行时间40s
这是典型可以进行静态函数改写内联表值函数的sql：
改写后：
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
对应的表值函数：
CREATE FUNCTION [dbo].[tvf_GetAvgPreferencePoints] (@DrawTicketID INT) RETURNS TABLE WITH SCHEMABINDING AS 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
改写后执行时间从40s降低到16s，对于倾斜列的优化速度更为明显
感谢各位的阅读，以上就是“SQL Server中怎么改写内联表值函数”的内容了，经过本文的学习后，相信大家对SQL Server中怎么改写内联表值函数这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是创新互联，小编将为大家推送更多相关知识点的文章，欢迎关注！
本文标题：SQLServer中怎么改写内联表值函数
当前网址：http://azwzsj.com/article/gdepjh.html
