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HomeBackend DevelopmentPHP Tutorial一个学生的多门课的关联表查询?

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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