mysql - 如何使用 statement update from 更新 mysql 表？

Question

我需要使用类(class)表中为所有参加名为“类(class)名称”的类(class)的客户提供的适当费用更新注册表

update from enrollment as e
    join course as c on c.coursenumber = e.coursenumber
    join customer as cs on cs.customernumber = e.customernumber 
set e.amountpaid = course.fee
where e.coursenumber in (select coursenumber from course where course = 'COURSE   NAME');

这在 mysql 中可能吗？一般来说，我是这个 DBMS 和 sql 的新手。

Answer 1

只需删除 FROM 关键字即可。

update enrollment as e
    join course as c on c.coursenumber = e.coursenumber
    join customer as cs on cs.customernumber = e.customernumber 
set e.amountpaid = course.fee
where e.coursenumber in (select coursenumber from course where course = 'COURSE   NAME');

或者直接不用 IN

update enrollment as e
    join course as c on c.coursenumber = e.coursenumber
    join customer as cs on cs.customernumber = e.customernumber 
set e.amountpaid = course.fee
where  c.course = 'COURSE   NAME';