Php 他数到四以上

没有经过这样的测试

SELECT a1.id, a1.user_id, a1.post_id, COUNT(a1_plus.id) AS other_count
FROM articles as a1
INNER JOIN articles a1_plus
ON a1.user_id = a1_plus.user_id
AND a1.date <= a1_plus.date
WHERE a1.user_id IN (3,14,1,2,3,4,5,6,7,8,9,10,11,12,14,15,16,17,18,19,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,38,39,13,114,1111,12,223,2234,225,226,227,228,229,2210)
GROUP BY a1.id, a1.user_id, a1.post_id
HAVING other_count <= 4

选择a1.id、a1.user\u id、a1.post\u id、COUNT（a1\u plus.id）作为其他\u计数
从文章中选择a1
内部连接条款a1_plus
在a1.user\U id=a1\U+1.user\U id上
a1.date可能重复的@MarcB您立即标记了这一点，但它不是重复的，我正在寻找另一种解决方案，以替代Baron Schwartz提供的答案。如果可能的话，我希望将繁重的工作从查询中转移到应用程序中。您想根据什么进行分组？您是否正在尝试获取每个用户最近4篇文章的列表？@noz:查询有点奇怪，非常奇怪。问题中的查询不起作用（文章id未定义）。解释涉及到另一个查询（s1来自哪里？）。注意：此查询的结果集与OP问题中查询的结果集明显不同。这是非常明显的-因此在开始时有“一点假设”。
id  select_type table   type    possible_keys   key key_len ref rows    Extra
1   PRIMARY <derived2>  ALL         NULL    NULL    NULL    NULL    10516   Using where
2   DERIVED <derived4>  system      NULL    NULL    NULL    NULL    1   
2   DERIVED <derived3>  ALL         NULL    NULL    NULL    NULL    10516   
4   DERIVED NULL        NULL        NULL    NULL    NULL    NULL    NULL    No tables used
3   DERIVED s1          ALL         Reco... NULL    NULL    NULL    1180931 Using filesort

SELECT a.id
     , a.user_id
     , a.post_id
  FROM articles a
 WHERE a.user_id IN (3,14,1,2,3,4,5,6,7,8,9,10,11,12,...)
 ORDER BY a.date DESC

@group = a2.user_id

Date       user   id        Date       user   id
---------- ------ --        ---------- ------ --
2103-07-22 abc     1        2103-07-22 abc     1
2103-07-22 abc     2        2103-07-22 abc     2
2103-07-22 abc     3        2103-07-22 abc     3
2103-07-22 EFGHI   4        2103-07-22 abc     5
2103-07-22 abc     5        2103-07-22 abc     6
2103-07-22 abc     6        2103-07-22 abc     7
2103-07-22 abc     7        2103-07-22 EFGHI   4

7 rows selected.            5 rows selected.

SET @gr=0, @row=0;
SELECT 
    id,user_id,post_id,row_number
FROM
    (SELECT 
        id,
            user_id,
            post_id,
            @row:=if(user_id <> @gr, 0, @row + 1) as row_number,
            @gr:=user_id
    FROM
        articles
    WHERE
        user_id IN (3 , 14, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 38, 39, 13, 114, 1111, 12, 223, 2234, 225, 226, 227, 228, 229, 2210)
    ORDER BY user_id , date DESC) as a1
WHERE
    row_number < 4

SELECT a1.id, a1.user_id, a1.post_id, COUNT(a1_plus.id) AS other_count
FROM articles as a1
INNER JOIN articles a1_plus
ON a1.user_id = a1_plus.user_id
AND a1.date <= a1_plus.date
WHERE a1.user_id IN (3,14,1,2,3,4,5,6,7,8,9,10,11,12,14,15,16,17,18,19,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,38,39,13,114,1111,12,223,2234,225,226,227,228,229,2210)
GROUP BY a1.id, a1.user_id, a1.post_id
HAVING other_count <= 4