选择categoryId的行属于2个或更多值

Question

我有一张这样的表：

我想找到courseId属于2个或更多categoryIds的courseId。例如。如果我将categoryId设为18112和21115，那么它应该只给出courseIds - 18602＆amp; 21101

我该怎么做？

Answer 1

按courseId分组，只选择那些拥有这两个categoryId s

的人

select courseId
from your_table
where categoryId in (18112,21115)
group by courseId
having count(distinct categoryId) = 2

Answer 2

select courseId 
from courses_categories
where categoryId in (18112,21115)
group by courseId
having count(distinct categoryId) >= 2

Answer 3

Group by和Having条款可以帮助您。

select courseId
from your_table
where categoryId in (18112,21115)
group by courseId
having count(distinct categoryId) >= 2

Answer 4

您可以使用GROUP BY和HAVING，如下所示：

SELECT courseId
FROM table_name
WHERE categoryId IN (18112,21115)
GROUP BY courseId
HAVING COUNT(DISTINCT categoryId) >= 2