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SQLServer并发问题,先SELECT后UPDATE,避免并发脏读情况解决

在SQL Server中,需要对数据操作进行先SELECT 之后UPDATE,对于这样的操作,如果出现高并发,可能导致脏读情况的发生。不能保证数据的同步。

解决方案是在事物中对表进行加更新锁:

事务一:

begin tran declare @count int =0select @count=[Count] from tb_name WITH(UPDLOCK,HOLDLOCK) where id=1select @count as count1waitfor delay 00:00:30update tb_name set [Count]=@count+1 where id=1commit tran  select * from tb_name

事务二:

begin trandeclare @count int =0select @count=[Count] from tb_name WITH(UPDLOCK,HOLDLOCK) where  id=1select @count as count2update tb_name set [Count]=@count+1 where id=1commit tran  select * from tb_name

 

SQLServer并发问题,先SELECT后UPDATE,避免并发脏读情况解决