php - 为什么将 count() 添加到我的 sql 查询中会使其无法工作？

Question

为什么返回 23 行(正确的数量):

select users.user_id, users.fname, users.lname, 
       stars.stars, comments.comment from users 
       LEFT JOIN stars on users.user_id = stars.userid 
       JOIN comments on users.user_id = comments.sender 
       where users.user_id = ? order by comments.time desc;

这会返回 1 行？:

select users.user_id, users.fname, users.lname,
       stars.stars, count(distinct comments.id) as amount,
       comments.comment from users 
       LEFT JOIN stars on users.user_id = stars.userid 
       JOIN comments on users.user_id = comments.sender 
       where users.user_id = ? order by comments.time desc;

干杯。

Answer 1

需要对主数据进行分组或者对字段进行子查询。