数据库编程基本练习题
作者:互联网
1、用一条SQL语句查询出每门课都大于80分的学生姓名
准备数据的sql代码:
create table score( id int primary key auto_increment, name varchar(20), subject varchar(20), score int); insert into score values (null,'张三','语文',81), (null,'张三','数学',75), (null,'李四','语文',76), (null,'李四','数学',90), (null,'王五','语文',81), (null,'王五','数学',100), (null,'王五 ','英语',90);
答案:
select distinct name from score name not in (select distinct name from score where score<=80)
2、每个月份的发生额都比101科目多的科目
请用SQL语句实现:从TestDB数据表中查询出所有月份的发生额都比101科目相应月份的发生额高的科目。请注意:TestDB中有很多科目,都有1-12月份的发生额。 AccID:科目代码,Occmonth:发生额月份,DebitOccur:发生额。 数据库名:JcyAudit,数据集:Select * from TestDB
准备数据的sql代码: drop table if exists TestDB; create table TestDB( id int primary key auto_increment, AccID varchar(20), Occmonth date, DebitOccur bigint); insert into TestDB values (null,'101','1988-1-1',100), (null,'101','1988-2-1',110), (null,'101','1988-3-1',120), (null,'101','1988-4-1',100), (null,'101','1988-5-1',100), (null,'101','1988-6-1',100), (null,'101','1988-7-1',100), (null,'101','1988-8-1',100); --复制上面的数据,故意把第一个月份的发生额数字改小一点 insert into TestDB values (null,'102','1988-1-1',90), (null,'102','1988-2-1',110), (null,'102','1988-3-1',120), (null,'102','1988-4-1',100), (null,'102','1988-5-1',100), (null,'102','1988-6-1',100), (null,'102','1988-7-1',100), (null,'102','1988-8-1',100); --复制最上面的数据,故意把所有发生额数字改大一点 insert into TestDB values (null,'103','1988-1-1',150), (null,'103','1988-2-1',160), (null,'103','1988-3-1',180), (null,'103','1988-4-1',120), (null,'103','1988-5-1',120), (null,'103','1988-6-1',120), (null,'103','1988-7-1',120), (null,'103','1988-8-1',120); --复制最上面的数据,故意把所有发生额数字改大一点 insert into TestDB values (null,'104','1988-1-1',130), (null,'104','1988-2-1',130), (null,'104','1988-3-1',140), (null,'104','1988-4-1',150), (null,'104','1988-5-1',160), (null,'104','1988-6-1',170), (null,'104','1988-7-1',180), (null,'104','1988-8-1',140); --复制最上面的数据,故意把第二个月份的发生额数字改小一点 insert into TestDB values (null,'105','1988-1-1',100), (null,'105','1988-2-1',80), (null,'105','1988-3-1',120), (null,'105','1988-4-1',100), (null,'105','1988-5-1',100), (null,'105','1988-6-1',100), (null,'105','1988-7-1',100), (null,'105','1988-8-1',100);
答案:
select distinct AccID from TestDB where AccID not in (select TestDB.AccIDfrom TestDB, (select * from TestDB where AccID='101') as db101 where TestDB.Occmonth=db101.Occmonth and TestDB.DebitOccur<=db101.DebitOccur );
3、统计每年每月的信息
year month amount 1991 1 1.1 1991 2 1.2 1991 3 1.3 1991 4 1.4 1992 1 2.1 1992 2 2.2 1992 3 2.3 1992 4 2.4 查成这样一个结果: year m1 m2 m3 m4 1991 1.1 1.2 1.3 1.4 1992 2.1 2.2 2.3 2.4
准备sql语句: drop table if exists sales; create table sales( id int auto_increment primary key, year varchar(10), month varchar(10), amount float(2,1)); insert into sales values (null,'1991','1',1.1), (null,'1991','2',1.2), (null,'1991','3',1.3), (null,'1991','4',1.4), (null,'1992','1',2.1), (null,'1992','2',2.2), (null,'1992','3',2.3), (null,'1992','4',2.4);
答案:
select sales.year, (select t.amount from sales as t where t.month='1' and t.year = sales.year) as 'm1', (select t.amount from sales as t where t.month='2' and t.year = sales.year) as 'm2', (select t.amount from sales as t where t.month='3' and t.year = sales.year) as 'm3', (select t.amount from sales as t where t.month='4' and t.year = sales.year) as 'm4' from sales group by year
未完待续~~~~~~~~~
标签:练习题,数据库,编程,sales,1988,TestDB,year,100,null 来源: https://www.cnblogs.com/zhuifeng-mayi/p/11099314.html