请参阅SQL Fiddle with demo

Question

这是我的数据表结构

    id     actor_id   created_at              updated_at 

    729    80         2012-09-10 17:05:59    2012-09-10 17:05:59
    731    80         2012-09-10 17:04:02    2012-09-10 17:04:02
    725    139        2012-09-06 13:59:08    2012-09-06 13:59:08
    724    76         2012-09-06 11:31:30    2012-09-06 11:31:30
    723    29         2012-09-06 09:40:22    2012-09-06 09:40:22
    719    29         2012-09-06 09:24:02    2012-09-06 09:24:02
    811    80         2012-09-02 17:05:59    2012-09-10 17:05:59
    812    80         2012-09-01 17:04:02    2012-09-10 17:04:02

这是

的结果

SELECT  `te`.`id`, te.actor_id, te.created_at, te.created_at
FROM `timeline_events` AS te
ORDER BY 
    te.created_at DESC
    LIMIT 10

我需要通过actor_id和created_at

对其进行分组

以下是我最终需要的内容

    id    actor_id     created_at          updated_at             count

    729    80       2012-09-10 17:05:59    2012-09-10 17:05:59     2
    725    139      2012-09-06 13:59:08    2012-09-06 13:59:08     1
    724    76       2012-09-06 11:31:30    2012-09-06 11:31:30     1
    723    29       2012-09-06 09:40:22    2012-09-06 09:40:22     2
    812    80       2012-09-10 17:04:02    2012-09-10 17:04:02     2

有人可以指导我怎么做吗？

非常感谢提前

UPD 为了简化，我将再举一个例子

所以说我有下一行

1                                             1 (count: 2)
1
3                                             3 (count: 1)
4
4     => after magic function it should be    4 (count: 2)
1
1                                             1 (count: 3)
1
6                                             6 (count: 2)
6
4                                             4 (count 3)
4
4

所以应该按小组分开。

UPD 2 我需要这个查询来渲染时间轴。现在它显示了用户所做的所有信息，但我需要将其分组。

在

user1上传照片
user1更改了信息
user2 updated bio
user3上传了照片
user3 updated bio
user1 update bio

在

user1上传照片并更改了信息
user2 updated bio
user3上传了照片并更新了生物
user1 updated bio

Answer 1

我认为这可能就是你要做的事情：

select t1.id,
  t1.actor_id,
  max(created_at) created_at,
  updated_at,
  t2.total
from yourtable t1
left join
(
  select count(*) total, date(created_at) dt, actor_id
  from yourtable
  group by actor_id, date(created_at)
) t2
  on t1.actor_id = t2.actor_id
  and date(t1.created_at) = t2.dt
group by  t1.actor_id, date(t1.created_at)
order by t1.created_at desc

请参阅SQL Fiddle with demo

我按actor_id分组，使用DATE()功能

分组日期

Answer 2

我自己找到解决方案

这是查询

SET @i = 0;
SELECT
    COUNT(`wrapper`.`id`) AS 'count',
    GROUP_CONCAT(`wrapper`.`type` SEPARATOR ',') as 'types'
FROM (
    SELECT  
        @prev := (
            SELECT prev_te.actor_id
            FROM `timeline_events` AS prev_te
            WHERE prev_te.created_at > te.created_at
            ORDER BY prev_te.created_at ASC
            LIMIT 1
        ) AS 'prev_actor_id',
        IF(
            @prev = te.`actor_id` OR @prev IS NULL, 
            @i, 
            @i := @i + 1
        ) AS 'actor_id_group',
        `te`.*
    FROM `timeline_events` AS te
    ORDER BY 
        te.created_at DESC, 
        te.id DESC
) AS `wrapper`
GROUP BY `wrapper`.`actor_id_group`
LIMIT 10

这里是the proof link; - ）

This website真的帮助了我

我正在使用包装器进行分组，因为mysql没有按变量分组，如果有人知道更好的解决方案，请告诉我

Answer 3

在GROUP BY actor_id子句之前添加order by。

最新编辑： select distinct actor_id, count(actor_id), created_at from actors group by actor_id order by created_at desc;

Answer 4

SELECT te。id，te.actor_id，te.created_at，te.updated_at， COUNT（*）FROM timeline_events AS te GROUP BY te.actor_id， te.created_at ORDER BY te.created_at DESC 限制10

组合类似的项目

4 个答案:

请参阅SQL Fiddle with demo