MySQL：我每天需要从每个用户的1个帖子到最多n个帖子显示

MySQL：我每天需要从每个用户的1个帖子到最多n个帖子显示

试试这个糟糕的SQL代码:)

select post_id, user_id, post_datetime, post_text from (  select posts.*,    if (user_id = @prev_user and date(post_datetime) = date(@prev_day),      @row := @row + 1, @row := 1) idx,    @prev_user := user_id,    @prev_day := post_datetime  from posts, (select @row := 1, @prev_user := null, @prev_day := null) init  order by date(post_datetime), user_id, post_datetime desc) swhere s.idx <= 2

结果：

+---------+---------+---------------------------------+----------------+| POST_ID | USER_ID |          POST_DATETIME          |   POST_TEXT    |+---------+---------+---------------------------------+----------------+|       4 |     100 | December, 01 2012 04:00:00+0000 | lorem ipsum 4  ||       2 |     100 | December, 01 2012 02:00:00+0000 | lorem ipsum 2  ||       3 |     101 | December, 01 2012 03:00:00+0000 | lorem ipsum 3  ||       5 |     102 | December, 01 2012 05:00:00+0000 | lorem ipsum 5  ||       6 |     100 | December, 02 2012 03:00:00+0000 | lorem ipsum 6  ||      10 |     101 | December, 02 2012 07:00:00+0000 | lorem ipsum 10 ||       9 |     101 | December, 02 2012 06:00:00+0000 | lorem ipsum 9  ||       7 |     102 | December, 02 2012 04:00:00+0000 | lorem ipsum 7  |+---------+---------+---------------------------------+----------------+

在这里摆弄。

我认为如果按日期降序排序会更合适，因为实际上是最接近当前日期的前2位。