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  • SQL Server 表连接删除

    一哥们在做数据同步的时候写了个游标去循环更新数据库里面的表记录:

    -- Following is incremental update 

    DECLARE @InterfaceCode_tmp varchar(12), @Affiliate_tmp char(3),@DealerNumber_tmp varchar(5),@DSPNumber_tmp varchar(12) 

    --Process DealerAuthorization 

    DECLARE dealerAuth_cursor CURSORFOR

    SELECT InterfaceCode,Affiliate,DealerNumber FROM DealerAuthorization_tmp

    OPEN dealerAuth_cursor

    FETCHNEXTFROM dealerAuth_cursor INTO @InterfaceCode_tmp,@Affiliate_tmp,@DealerNumber_tmp

    WHILE@@FETCH_STATUS= 0

    BEGIN 

    DELETE DealerAuthorization WHERE InterfaceCode=@InterfaceCode_tmp and Affiliate=@Affiliate_tmp and DealerNumber=@DealerNumber_tmp 

    INSERT INTO DealerAuthorization (InterfaceCode, Affiliate, DealerNumber, isValid,ExpireDate)

    SELECT InterfaceCode, Affiliate, DealerNumber, isValid, ExpireDate

    FROM DealerAuthorization_tmp WHERE InterfaceCode=@InterfaceCode_tmp and Affiliate=@Affiliate_tmp and DealerNumber=@DealerNumber_tmp

    FETCH NEXTF ROM dealerAuth_cursor INTO @InterfaceCode_tmp,@Affiliate_tmp,@DealerNumber_tmp

    END

    CLOSE dealerAuth_cursor

    DEALLOCATE dealerAuth_cursor

    尼玛,我们数据库有5万多条数据,我不知道要执行多久。还好数据都不是很大,栏位也不多,他说只用一秒就完了。

    想起以前写过一个,帮他改了下

    DELETE  FROM DealerAuthorization

    FROM  DealerAuthorization a inner join DealerAuthorization_tmp b

    ON  a.DealerNumber = b.DealerNumber and a.Affiliate = b.Affiliate and a.InterfaceCode = b.InterfaceCode

    INSERT  INTO  DealerAuthorization(InterfaceCode, Affiliate, DealerNumber, isValid,ExpireDate)

    SELECT  InterfaceCode, Affiliate, DealerNumber, isValid,ExpireDate

    FROM  DealerAuthorization_tmp

    看起来舒服多了。嘿嘿。

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  • 原文地址:https://www.cnblogs.com/JasonLiao/p/2528535.html
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