2021到了最后一个月份,年后肯定有蛮多小伙伴需要跳槽换工作,但对于年限稍短的软件测试工程师,难免会需要进行笔试,而在笔试中,基本都会碰到一道关于数据库的大题,今天这篇文章呢,就收录了下最近学员反馈上来的一些数据库笔试真题,包含答案!
1、依据以下学生表、班级表,按要求写 SQL
答案:
1、 select * from student a left join class b on a.c_id = b.id where score = ( select max(score) from student)
2、 select b.name,count(*),avg(score) as avgScore from student a,class b where a.c_id = b.id group by b.name order by avgScore;
答案:
(1)select ID from A where name = '李四'; (2)select NO,NAME,ID from A,B where A.NO = B.NO AND DEPOSIT >= 1000; (3)select COUNTRY,count(*) FROM A GROUP BY COUNTRY;
(4)SELECT '80 后' as 年龄段,sum(CREDIT) AS '信用卡余额' FROM A,B WHERE A.NO = B.NO AND BIRTH >= 19800101 AND BIRTH < 19900101 UNION SELECT '90 后' as 年龄段,sum(CREDIT) AS '信用卡余额' FROM A,B WHERE A.NO = B.NO AND BIRTH >= 19900101 AND BIRTH < 20000101;
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原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
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原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。