mysql - 当同时存在 LIMIT 和 JOIN 子句时，如何计算所有行数？

Question

这是我的查询:

select u.id, u.name,
       (select count(*) from users where name = u.name) as total
from users u
where u.name = 'anything'
order by id
limit 1

如您所知，我的查询返回 1 个具有任意名称的用户。 total 包含具有anything 名称的所有用户的数量。好的，一切都好。

<小时/>

现在，当查询中有三个 JOIN 时，我想做同样的事情。请假设:

select u.id, u.name, sum(r.reputation) rep
from users u
join reputation r on u.id = r.user_id
join posts_tags pt on r.post_id = pt.post_id
join tags t on pt.tag_id = t.id 
where u.name = 'anything' and t.name = 'mytag'
group by u.id, u.name
order by rep desc, u.id
limit 1

现在我想知道，如何在此 ^ 查询中实现 total 部分？

Answer 1

尝试这个查询，希望这能给您正确的结果。

 select * , count(id) as total from  (select u.id, u.name, sum(r.reputation) rep 
        from users u
        join reputation r on u.id = r.user_id
        join posts_tags pt on r.post_id = pt.post_id
        join tags t on pt.tag_id = t.id 
        where u.name = 'anything' and t.name = 'mytag'
        group by u.id, u.name
        order by rep desc, u.id
        limit 1 ) as result