使用PHP对大量MySQL表进行分组和排序

我试图根据一条记录在下载表中出现的次数，在多个表上按DESC顺序输出一系列连接的记录

资源数据（资源数据）：

----------------------------------------
| ID  |  Contributor ID |     Title    |
----------------------------------------
|  1  |        111      |  Resource A  |
|  2  |        222      |  Resource B  |
|  3  |        333      |  Resource C  |
|  4  |        222      |  Resource D  |
|  5  |        111      |  Resource E  |
----------------------------------------

----------------------
|   ID  |  User Name |
----------------------
|  111  |   User X   |
|  222  |   User Y   |
|  333  |   User Z   |
----------------------

---------------------
|  ID | Resource ID |
---------------------
|  1  |      4      |
|  2  |      1      |
|  3  |      4      |
|  4  |      3      |
|  5  |      4      |
|  6  |      4      |
|  7  |      2      |
|  8  |      5      |
|  9  |      4      |
|  10 |      5      |
---------------------

贡献者数据（贡献者数据）：

----------------------------------------
| ID  |  Contributor ID |     Title    |
----------------------------------------
|  1  |        111      |  Resource A  |
|  2  |        222      |  Resource B  |
|  3  |        333      |  Resource C  |
|  4  |        222      |  Resource D  |
|  5  |        111      |  Resource E  |
----------------------------------------

----------------------
|   ID  |  User Name |
----------------------
|  111  |   User X   |
|  222  |   User Y   |
|  333  |   User Z   |
----------------------

---------------------
|  ID | Resource ID |
---------------------
|  1  |      4      |
|  2  |      1      |
|  3  |      4      |
|  4  |      3      |
|  5  |      4      |
|  6  |      4      |
|  7  |      2      |
|  8  |      5      |
|  9  |      4      |
|  10 |      5      |
---------------------

下载数据（下载数据）：

----------------------------------------
| ID  |  Contributor ID |     Title    |
----------------------------------------
|  1  |        111      |  Resource A  |
|  2  |        222      |  Resource B  |
|  3  |        333      |  Resource C  |
|  4  |        222      |  Resource D  |
|  5  |        111      |  Resource E  |
----------------------------------------

----------------------
|   ID  |  User Name |
----------------------
|  111  |   User X   |
|  222  |   User Y   |
|  333  |   User Z   |
----------------------

---------------------
|  ID | Resource ID |
---------------------
|  1  |      4      |
|  2  |      1      |
|  3  |      4      |
|  4  |      3      |
|  5  |      4      |
|  6  |      4      |
|  7  |      2      |
|  8  |      5      |
|  9  |      4      |
|  10 |      5      |
---------------------

排序后，数据应显示如下内容（不是格式，只是内容）：

到目前为止，我有这段代码，但它只输出了一条记录（应该有很多条，根据查询限制为4条）

---

您需要的是一个

GROUP BY

子句来对下载数据表中的资源id记录进行分组，如下所示

SELECT contributor_data.id, resource_data.id, resource_data.title,
       contributor_data.username, COUNT(download_data.id) AS records
FROM resource_data
JOIN contributor_data
     ON resource_data.contributor_id = contributor_data.id
JOIN download_data
     ON resource_data.id = download_data.resource_id
GROUP BY download_data.resource_id
ORDER BY records DESC;

这将为您提供所需的结果，因为您现在可以基于GROUP BY（因为ORDER BY发生在分组完成之后）为计数结果别名

所以你的最终结果看起来更像你想要的

+------+------+------------+----------+---------+
| id   | id   | title      | username | records |
+------+------+------------+----------+---------+
|  222 |    4 | Resource D | User Y   |       5 |
|  111 |    5 | Resource E | User X   |       2 |
|  222 |    2 | Resource B | User Y   |       1 |
|  333 |    3 | Resource C | User Z   |       1 |
|  111 |    1 | Resource A | User X   |       1 |
+------+------+------------+----------+---------+

这是一个