通过不同表中的数据对mysql表进行排序

Question

我必须使用mysql表并尝试显示table1的结果，但要按table2进行排序。 对于表2，我计算重复ID的所有出现次数，然后将结果降序显示。 下面是我能得到的，想知道是否可以通过单个查询完成。

$query = "
SELECT DISTINCT   registration.* 

FROM              registration 

INNER JOIN        downloads 
ON                registration.id = downloads.id 

GROUP BY          downloads.COUNT(id) 
ORDER BY          downloads.COUNT(id) DESC,
                  downloads.COUNT(id) DESC

“;

Answer 1

我认为您需要遵循以下原则：

SELECT Registration.id, Registration.name, Registration.email,
       Downloads.document
FROM Registration
JOIN Downloads
  ON Downloads.id = Registration.id
JOIN (SELECT id, COUNT(*) as count
      FROM Downloads
      GROUP BY id) Download_Count
  ON Download_Count.id = Registration.id
ORDER BY Download_Count.count DESC

（未经测试，因为OP可以在问题中提供示例数据和表格布局）