mysql分组groupby子查询count优化
百年菜鸟 2018-02-03 03:45:59 SELECT
a.id,
a.proimg,
a.projectname,
a.datecreated AS date,
a.studyCount AS courseCount,
(SELECT count(1) FROM b WHERE b.proid= a.id) AS materialCount
FROM a
LEFT JOIN c ON c.id = a.projectsource
WHERE 1 = 1
AND a.id NOT IN ('uuceacgkqjlcg5rdlg7zla','uz6eacgkzpnizkuk-ysalw','vsqcacgkpzposa5myqrmxg')
ORDER BY
studyCount DESC,
materialCount DESC,
DATE ASC