mysql - SQL:对行进行计数和分组

Question

id | userid | exerciseid | date                | time | weight | distance | reps
1  | 24     | 1          | 2013-09-28 00:00:00 | 2321 | 231    | 121      | NULL
2  | 24     | 24         | 2013-09-28 00:00:00 | 2321 | 231    | 121      | NULL
3  | 24     | 1          | 2013-09-28 00:00:00 | 2321 | 231    | 121      | NULL
4  | 24     | 1          | 2000-00-00 00:00:00 | NULL | 100    | NULL     | 2
5  | 24     | 1          | 2013-09-28 00:00:00 | 2321 | 231    | 121      | NULL

第 1、3 和 5 行相同。我想做一个将它们分组在一起的计数，同时还添加一个包含计数值的列。

SELECT id, userid, exerciseid, date, time, weight, distance, reps    
FROM `exercises`
WHERE `userid` = 1 AND `date` < now()

所以我希望它也返回类似的东西:

id | userid | exerciseid | date                | time | weight | distance | reps | count
1  | 24     | 1          | 2013-09-28 00:00:00 | 2321 | 231    | 121      | NULL | 3
4  | 24     | 1          | 2000-00-00 00:00:00 | NULL | 100    | NULL     | 2    | NULL

Answer 1

试试这个

SELECT id, userid, exerciseid, date, time, weight, distance, reps,
       count(*) as count
FROM `exercises`
WHERE userid = 1 AND date < now()
GROUP BY id, userid, exerciseid, date, time, weight, distance, reps