急救,如何用SQL语句实现下面功能?
一个表中一,两个字段,department,score,表示院系号及考试分数,现想按院系分类查询各分数区间统计数量,如:
统计90-100分有多少个,80-90分的有多少个,不及格的有多少个
不知如何解决
问题点数:50、回复次数:5Top
1 楼shaoshaoh(汤勺)回复于 2006-05-02 21:15:37 得分 0
一个表中一,两个字段,department,score,表示院系号及考试分数,
现想按院系分类查询各分数区间统计数量,如:
统计90-100分有多少个,80-90分的有多少个,不及格的有多少个
不知如何解决
select count(score)
form table
where department = math and score >90
照这个样子写三个吧,
本人技术也不行,
就能想到这个样子
希望对你有启发……Top
2 楼scmail81(琳·风の狼(修罗))回复于 2006-05-02 21:15:49 得分 45
select department,
sum(case when score>90 and score<=100 then 1 else 0 end) as '90-100',
sum(case when score>80 and score<=90 then 1 else 0 end) as '80-90',
sum(case when score<60 then 1 else 0 end) as '不及格'
from 表
group by departmentTop
3 楼terryjim(jim)回复于 2006-05-02 21:27:26 得分 0
唉,我真是笨啊,多谢了!Top
4 楼zhenmeiyisi(。。。)回复于 2006-05-02 21:28:24 得分 5
试试这个 。。。
SELECT department, COUNT(*) AS Expr1
FROM tb
WHERE (score >= 90) AND (score <= 100)
GROUP BY department
UNION ALL
SELECT department, COUNT(*) AS Expr1
FROM tb
WHERE (score >= 80) AND (score <90)
GROUP BY departmentTop
5 楼terryjim(jim)回复于 2006-05-02 21:36:05 得分 0
呵呵,还是scmail81老兄的方法简单明了些,多谢大家了Top




