我有这个查询
SELECT DISTINCT
u.email,
(
SELECT
count(DISTINCT o.id)
FROM
orders o
INNER JOIN cart_dates cd ON cd.order_id = o.id
WHERE
u.id = o.user_id
) as count
FROM
users u
[仅当count
为<20时如何才能获得行?
您可以使用group by
和having
子句。
select u.email
from users u
inner join orders o on o.user_Id = u.id
inner join card_dates cd on cd.order_id = o.id
group by u.email
having count(distinct o.id) < 20