mysql 错误。 #1111 - Invalid use of group function

Question

// #1242 - Subquery returns more than 1 row
SELECT (sum(view)-max(view)-min(view))/(count(media_id)-2),count(media_id) 
FROM ms_media_share as a 
WHERE ( select count(media_id) from ms_media_share group by media_id ) 
NOT IN (1,2,3) 
GROUP BY media_id

// #1111 - Invalid use of group function
SELECT (sum(view)-max(view)-min(view))/(count(media_id)-2),count(media_id) 
FROM ms_media_share as a 
WHERE count(media_id) > 3
GROUP BY media_id

// 可行
SELECT (sum(view)-max(view)-min(view))/(count(media_id)-2),count(media_id) 
FROM ms_media_share as a 
GROUP BY media_id

求助，谁知道原因的麻烦告诉一下，谢谢

Answer 1

你不可能同时又group by一列，同时又要去count这同一列，你要想count的话，count别的列才行。