本文介绍了一种通过创建删除触发器来解决因未设置主外键而导致的数据库冗余问题的方法。具体步骤包括：为受影响的数据表创建触发器，在删除主表记录时同步清理相关联的子表记录。
由于当初在设计数据库的时候没有建立主外键关系，导致删除主表后，会在其他表产生许多冗余数据，因此需要添加删除触发器。
create trigger trgContentSet
on contentset
for Delete
as
delete attendermanger from attendermanger as a,deleted d where a.d_cid = d.c_id
delete attenderdep from attenderdep as a,deleted d where a.contentset = d.c_id
delete checkdetails from checkdetails as c,deleted d where c.d_cid = d.c_id
create trigger trgContentSet
on contentset
for Delete
as
delete attendermanger from attendermanger as a,deleted d where a.d_cid = d.c_id
delete attenderdep from attenderdep as a,deleted d where a.contentset = d.c_id
delete checkdetails from checkdetails as c,deleted d where c.d_cid = d.c_id
扫一扫
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
