有子句mysql的嵌套计数？

Question

我想计算从不同类别中选择的图像，但下面的查询却返回错误

＃1064-您的SQL语法有误； 检查与您的MySQL服务器版本对应的手册以获取正确的语法，以在第2行附近使用'（select count（i1.id）as cnt FROM image_gallery i1 LEFT OUTER JOIN image_g'

我哪里错了？

SELECT count(*)
(select count(*)
FROM image_gallery i1
LEFT OUTER JOIN image_gallery i2
  ON (i1.category_id = i2.category_id AND i1.id < i2.id)
GROUP BY i1.id
HAVING COUNT(*) < 10 
) as total_pics

Answer 1

您错过了FROM关键字

SELECT sum(cnt)
FROM
(
  select count(i1.id) as cnt
  FROM image_gallery i1
  LEFT OUTER JOIN image_gallery i2 ON i1.category_id = i2.category_id 
                                  AND i1.id < i2.id
  GROUP BY i1.id
  HAVING COUNT(*) < 10 
) as total_pics