mysql视图操作和存储过程
欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入 1.MySQL 视图的操作是在新版本数据库才支持的,视图操作的好处是可以简化数据库的查询,特别是一些经常查询的数据表我们可以先创建一个视图,以后要在查询这个类式 的数据表时候,就可以直接查询该视
欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入
1.MySQL 视图的操作是在新版本数据库才支持的,视图操作的好处是可以简化数据库的查询,特别是一些经常查询的数据表我们可以先创建一个视图,以后要在查询这个类式 的数据表时候,就可以直接查询该视图。这样也可以提高查询的效率。
视图还有个好处就是,你如果改变了基数据表的字段或者值,视图表也会随着改 变,所以我们不用去担心,改变基数据的字段值时候担心视图的数据不同步的问题。
例如:创建视图,然后通过视图来查询。
create view v3 as SELECT b.sid, b.grade, c.cname
FROM grade b, course c
WHERE b.cid = c.cid
然后查询从视图中查询出一条数据
select sid,grade,cname from v3 where sid=200410001
这样是不是更好理解点,不要再一次使用联合查询去查询某条数据。
2存储过程,这 个操作可以使数据库操作更加的简洁,数据操作的重用性也得到了更好的体现,存储过程可以实现多表的操作,还有他他允许传入参数。具体的操作可以参考手册。
这 两个sql特征 可以在我们具体在实际开发灵活应用,也许可以改变一下我们过去一些不合理的数据库操作,可以使我们写的程序更加的合理,更加的易于维护。

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