目前,我正在执行一个查询,其中包含3个子查询,
所有查询都在同一张表上,
所有查询都有不同的where子句
我曾考虑过要进行小组合作,但这会破坏SUM()
这是查询
SELECT SUM(club) AS club,(SELECT COUNT(id) FROM action_6_members WHERE SUBSTR(CODE,1,1) = '9') AS 5pts,1) = 'A') AS 10pts,1) NOT IN('9','A')) AS General
FROM action_6_members;
这是解释
id select_type table type rows Extra 1 PRIMARY action_6_members ALL 1471 4 SUBQUERY action_6_members ALL 1471 Using where 3 SUBQUERY action_6_members ALL 1471 Using where 2 SUBQUERY action_6_members ALL 1471 Using where
最佳答案
采用：
原文链接：/mysql/532152.htmlSELECT SUM(club) AS club,SUM(CASE WHEN SUBSTR(CODE,1) = '9' THEN 1 ELSE 0 END) AS 5pts,1) = 'A' THEN 1 ELSE 0 END) AS 10pts,'A') THEN 1 ELSE 0 END) AS General
FROM action_6_members;