http://msdn.microsoft.com/en-us/library/ms175976.aspxUSE AdventureWorks;GOBEGIN TRANSACTION;BEGIN TRY    --Generate a constraint violation error.    DELETE FROM Production.Product    WHERE ProductID=980;END TRYBEGIN CATCH    SELECT         ER

<br />http://databases.about.com/od/sqlserver/a/isolationmodels.htm<br />Normally, it's best to allow SQL Server to enforce isolation between transactions in its default manner; after all, isolation is one of the basic tenets of the ACID model .H

<br />参考 : http://tech.ddvip.com/2008-09/122084673361639.html<br />锁 : 资源 vs. 并发<br /> <br />低级别的锁(e.g. 行锁) : 并发高, 资源占用高<br /> <br />高级别的锁(e.g. 表锁) : 并发低, 资源占用低<br /> <br />锁升级: 从低级别锁到高级别锁<br />为了提高系统的性能，加快事务的处理速度，缩短事务的等待时间，应该使锁定的资源最小化。<br /> <br />事务的类型