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。