mysql - 错误代码 : 1146. 表 'fe539.t' 不存在

Question

我在 MySQL 中遇到以下问题

问题出现在别名“T”

select course_id, sec_id, enrollment 
from (
    select course_id, sec_id, count(ID) as enrollment
    from section natural join takes
    where semester = 'Fall' and year =2009
    group by course_id, sec_id
) as T
where enrollment = (select max(enrollment) from T);

Answer 1

我认为，如果您没有抽牌，您可能会遇到类似以下的情况。

select course_id, sec_id, count(*) as enrollment
        from section s
        join takes t on s.sec_id = t.course_id
        where semester = 'Fall' and year =2009
        group by course_id, sec_id 
        order by count(*) desc 
        limit 1 
;