SQL DISTINCT加计数

Question

我目前有一张桌子，上面有专辑的名称，艺术家和标题（适用于Mp3）。 目前，我在左侧的网页上使用以下命令显示所有相册名称：

SELEC DISTINCT `album` FROM `mp3`

但我想显示每张专辑旁边的数量，例如：

A Very Good Album (3)

表示该记录中有3个整体。 我可以使用SQL吗？ 选择Distinct，还要找出这张专辑有多少张？

Answer 1

与其说是DISTINCT ， DISTINCT说是按album分组的基本COUNT()聚合 。

SELECT
  album,
  COUNT(*) AS num_records
FROM 
  mp3
GROUP BY album

如果要在SQL查询内的括号中使用它，请使用CONCAT() 。 不过，最好将其留给您的应用程序进行显示。

SELECT
  /* The album title, and count in () as one column as a single string */
  /* like "A Very Good Album (3)" */
  CONCAT(album, ' (', COUNT(*), ')') AS album 
FROM
  mp3
GROUP BY album

Answer 2

尝试这个：

SELECT `album`, COUNT(*) FROM `mp3` GROUP BY `album`

Answer 3

您想要一个group by ：

select album, count(*)
from mp3
group by album

Answer 4

使用group by并像这样连接字符串

SELECT
    CONCAT(`album`, ' (', COUNT(*), ')') as album
FROM `mp3`
GROUP BY `album`

Answer 5

看看Count()和Group By

Answer 6

SELECT DISTINCT CONCAT(album, ' (', COUNT(DISTINCT album), ')') AS album
FROM            mp3
GROUP BY        album