数据库小试题2
世纪佳缘网面试题
1.统计每个分类(type)有多少人:
select type,count(type) from tab_user group by type;
2.统计五个人的总分(score)是多少:
select sum(score) from tab_user;
3.按照分数(score)选出前三名,倒序排列:
select * from `tab_user` order by score desc limit 3;
4.插入数据:小明(name),4(type),30(score);
insert into `tab_user` (name,type,score) values ('小明','4','30');
5.更新50分一下(不含50分)的分数(score)为60;
update `tab_user` set score = 60 where score<50;
6.删除分数(score)60分一下的数据。
DELETE from `tab_user` where score <60;