本篇内容主要讲解“SqlServer怎么实现类似Oracle的before触发器”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“SqlServer怎么实现类似Oracle的before触发器”吧!

1. 插入数据前判断数据是否存在

SETANSI_NULLSONGOSETQUOTED_IDENTIFIERONGO--=============================================--Author:<Author,,Name>--Createdate:<CreateDate,,>--Description:<Description,,>--=============================================alterTRIGGERCategoryExistTriggerONProductCategoryinsteadofinsertASdeclare@categoryNamevarchar(50);BEGIN--SETNOCOUNTONaddedtopreventextraresultsetsfrom--interferingwithSELECTstatements.SETNOCOUNTON;--Insertstatementsfortriggerhereselect@categoryName=CategoryNamefrominserted;ifexists(select*fromProductCategorywhereCategoryName=@categoryName)beginprint'Categoryexists..'end;elsebegininsertintoProductCategoryselect*frominserted;end;END

2. 删除表中数据时需要先删除外键表的数据

SETANSI_NULLSONGOSETQUOTED_IDENTIFIERONGO--=============================================--Author:<Author,,Name>--Createdate:<CreateDate,,>--Description:<Description,,>--=============================================alterTRIGGERDeleteOrderTriggerONOrderHeaderinsteadofdeleteASdeclare@OrderIdvarchar(50);BEGINSETNOCOUNTON;select@OrderId=OrderIdfromdeleted;deletefromOrderLinewhereOrderId=@OrderId;ENDGO

到此，相信大家对“SqlServer怎么实现类似Oracle的before触发器”有了更深的了解，不妨来实际操作一番吧！这里是亿速云网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！