SQL SELECT 中的服务器不匹配行计数和具有相同条件的 UPDATE 查询

Question

我正在尝试将更新和 select 查询计数与相同条件相匹配。但是行数有很大的不同。

更新查询：

 UPDATE  MKP set MKP.Quantity =  MKP.Quantity + LQD.Quantity, ModifiedDate = GETDATE()
         FROM IM_MarketPlace MKP 
              INNER JOIN IM_ChannelListings CL ON MKP.ListingID = CL.ListingID 
              INNER JOIN @ListingQuantityData LQD ON LQD.ChanelListingID = RTRIM(LTRIM((CL.ChannelListingID)))  and LQD.SalesChannelID = CL.ChannelID
              Left outer join IM_ListingVariations LV on LV.ListingCode = RTRIM(LTRIM((LQD.VariationSKU))) and  MKP.ListingVariationID = LV.ID and CL.ListingID=LV.ListingID
         WHERE MKP.IsActive =1 and MKP.IsDeleted=0 and CL.IsActive =1 and CL.IsDeleted=0 
               AND (LQD.VariationSKU is null OR (LQD.VariationSKU = LV.ListingCode and lv.ID = MKP.ListingVariationID))

Select查询

select count(mkp.ListingID) FROM IM_MarketPlace MKP 
              INNER JOIN IM_ChannelListings CL ON MKP.ListingID = CL.ListingID 
              INNER JOIN @ListingQuantityData LQD ON LQD.ChanelListingID = RTRIM(LTRIM((CL.ChannelListingID)))  and LQD.SalesChannelID = CL.ChannelID
              Left outer join IM_ListingVariations LV on LV.ListingCode = RTRIM(LTRIM((LQD.VariationSKU))) and  MKP.ListingVariationID = LV.ID and CL.ListingID=LV.ListingID
         WHERE MKP.IsActive =1 and MKP.IsDeleted=0 and CL.IsActive =1 and CL.IsDeleted=0 
               AND (LQD.VariationSKU is null OR (LQD.VariationSKU = LV.ListingCode and lv.ID = MKP.ListingVariationID))

请帮我解决这个问题。

另外请告诉我@@rowcount 将如何用于更新查询。

Answer 1

如果连接中涉及的至少两个表之间存在一对多关系，就会发生这种情况。

SELECT 将对所有行进行计数，包括那些被联接乘以的行。 UPDATE 将只计算 IM_MarketPlace 中受 UPDATE.

影响的唯一行

在存在一对多关系的情况下，连接到 IM_MarketPlace 中特定行的 "many" 行中的哪些行用作该行更新中的源是不确定的。

SQL SELECT 中的服务器不匹配行计数和具有相同条件的 UPDATE 查询

SQL Server mismatch row count in SELECT and UPDATE query with same conditions

sql

sql-server

sql-server-2012

sql-server-2016

sql-server-2017