所以我有一个“书签”表,我试图获得具有最多内容书签的用户的“UserID”。此查询返回十个最活跃用户的UserID。这个查询对我来说是这样的并且有效:
SELECT COUNT(*) AS `Rows`, UserID FROM `bookmark`
WHERE UserID NOT IN(1, 2, 25, 38, 41, 43, 47, 125)
GROUP BY UserID ORDER BY `Rows` DESC LIMIT 10
现在我尝试将结果查询加入“accounts”表,通过将UserID与accounts表中的“id”进行比较来获取每个用户ID的所有信息。
SELECT COUNT(*) AS `Rows`, UserID FROM `bookmark`
join accounts ON accounts.ID = bookmark.UserID
WHERE UserID NOT IN(1, 2, 25, 38, 41, 43, 47, 125)
GROUP BY UserID ORDER BY `Rows` DESC LIMIT 10
这不会将任何行作为accounts表返回,而是返回与之前相同的结果。我需要能够获取帐户表的所有行(与使用*相同)
如果它有助于我的帐户表有这些行= user_name,id,email和我的书签表有这些rows = id,UserId,link
答案 0 :(得分:1)
一种解决方案是将group by
移动到子查询:
select *
from (
select count(*) as Rows
, UserID
from bookmark
where UserID not in (1, 2, 25, 38, 41, 43, 47, 125)
group by
UserID
) as BookmarkSubquery
join accounts
on accounts.ID = BookmarkSubquery.UserID
order by
BookmarkSubquery.Rows DESC
limit 10
另一种方法是通过以下方式将帐户中的列添加到组中:
select count(*) as Rows
, bookmark.UserID
, accounts.Name
, accounts.BirthDate
from bookmark
join accounts
on accounts.ID = BookmarkSubquery.UserID
where bookmark.UserID not in (1, 2, 25, 38, 41, 43, 47, 125)
group by
, bookmark.UserID
, accounts.Name
, accounts.BirthDate
order by
count(*) DESC
limit 10
注意:MySQL允许您仅列出bookmark.UserID
中的group by
;虽然这样可行,但不建议这样做。
答案 1 :(得分:0)
这可能很丑,但您可以将第一个查询存储在临时表中,然后在帐户和临时表之间进行连接。
另外,尝试进行左连接以查看是否有任何方式。有时这有助于调试查询。