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  • 视图、触发器

    视图:只能查询使用,不能新增数据和修改数据
    把一个查询结果当做一个虚拟表
    select *from (xunibiao) as xunibiaoming where 条件
    修改视图
    alter view shitu1
    as
    select *from studento
    删除视图
    drop view shitu1
    触发器
    ---触发器---特殊的存储过程。通过增删改数据库表来自动引发
    create trigger TR_student_insert
    on student--在哪个表上建立触发器
    for insert--for是新增之后触发,for还可以写成after——在什么什么之后触发
    as
    begin
    select *from student
    end
    go
    insert into student values()--括号是文件中的所有列

    create trigger TR_student_delete
    on student
    instead of delete
    as
    begin
    declare @sno int
    select @sno=sno from deleted
    delete from
    end
    go
    delete from student
    select *from student
    create trigger TR_student_delete
    on student
    instead of delete
    as
    begin
    select *from deleted--deleted 是临时表来获取数据
    end
    go

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  • 原文地址:https://www.cnblogs.com/liuyuwen900326/p/4149115.html
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