一个学生表
student
id name age six
1 张三 20 男
2 张四 19 男
语文表
id keben feishu sid
1 yuwen 90 1
数学表
id keben feishu sid
1 shuyue 90 1
物理表
id keben feishu sid
1 wuli 90 1
有很多学生的,怎么查询效率最高呢,就是比如查询张三的语文,数学和物理,这三个表字段名都是一样的,
回复讨论(解决方案)
表就有问题, 直接做1个表就行了分那么多有啥用
在用户表中增加语文数学物理分数字段,直接查就行了
如果怕用户表字段太多,可以将语文数学物理分数放到一个附表中,做正常的连表查询就行
是这样的,这只是一个例子,实际上这表的内容不只这些,
难倒各位了吧,求高手指点
你这个问题太抽象了,我想不出来场景
但是语文数学和物理如果字段都相同就没必要创建3个表,1个表就够了,表中增加一个type字段做区分
select * from user left join 成绩表 on user.id= 成绩表.uid where user.name='张三' and (type=‘语文’ or type=‘数学’ or type=‘物理’)
三个表中也不完全一样,好吧,谢谢你
其实就是一个学生查询这三张表里的有关内容,就这样啊
好吧,自己解决了

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