计算特定ID的行数

Question

在第一个表album中有{id}，第二个表album_details有sub_id，与album表id

相关

我需要显示单独id值的计数。

SELECT DISTINCT B.SUB_ID, A . * , B.CONTENT_VALUE AS detail, 
(SELECT COUNT( ID ) 
FROM album_details WHERE A.ID = B.SUB_ID ) AS count
FROM album AS A, album_details AS B
WHERE A.WEBSITE_ID =  '571710720'
AND A.ID = B.SUB_ID
GROUP BY B.SUB_ID
LIMIT 0 , 30

现在，count列显示所有行的40，但需要为'id = 4'显示'count'6，为'id = 2'显示'count'3

Answer 1

假设第一个表是A，第二个表是B，那么查询将是这样的

select a.ID, count(b.SUB_ID) AS total
FROM A LEFT JOIN B ON A.ID = B.SUB_ID
Group by B.SUB_ID.

它可能对你有所帮助。如果没有，请问。

Answer 2

GROUP BY是您的首选武器。

SELECT 
    a.ID,
    a.CONTENT_VALUE,
    COUNT(ad.ID)
FROM albums AS a
LEFT JOIN album_details AS ad ON a.ID = ad.SUB_ID
GROUP BY a.ID

您可以在WHERE之前添加GROUP BY。

Answer 3

从album_details中选择count（sub_id）作为count1，其中sub_id in（从专辑中选择id）WHERE album.WEBSITE_ID =＆＃39; 571710720＆＃39; AND album.ID = album_details.SUB_ID

Answer 4

SELECT count（SUB_ID），来自album_details组的SUB_ID SUB_ID