SELECT * from
(SELECT avg(score) as '英语平均成绩',sum(CASE WHEN score>=60 THEN 1 ELSE 0 END)/COUNT(*) as '英语及格率'
from SC WHERE c=3 ) a;
(SELECT avg(score) as '英语平均成绩',sum(CASE WHEN score>=60 THEN 1 ELSE 0 END)/COUNT(*) as '英语及格率'
from SC WHERE c=3 ) a;
解决方案 »
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??select * from (子查询)
按照刚才给的语句,只能这样写吗:SELECT * from
(SELECT avg(score) as '英语平均成绩',sum(CASE WHEN score>=60 THEN 1 ELSE 0 END)/COUNT(*) as '英语及格率'from SC WHERE c=3 ) a,
(SELECT avg(score) as '企业管理平均成绩',sum(CASE WHEN score>=60 THEN 1 ELSE 0 END)/COUNT(*) as '企业管理及格率'from SC WHERE c=2)b,
(SELECT avg(score) as '数据库平均成绩',sum(CASE WHEN score>=60 THEN 1 ELSE 0 END)/COUNT(*) as '数据库及格率' from SC WHERE c=1)c
from SC WHERE c=3 ),(SELECT avg(score) as '英语平均成绩' from SC WHERE c=3)
这个语句可以执行
(SELECT avg(score) as '英语平均成绩',sum(CASE WHEN score>=60 THEN 1 ELSE 0 END)/COUNT(*) as '英语及格率'
from SC WHERE c=3 ) t;