day3-mysql查询与函数
day3-mysql查询与函数查询练习1-企业人事管理系统查询练习2-图书借阅管理mysql常用函数
查询练习1-企业人事管理系统
建表：
--部门表 CREATE TABLE `department` ( `Depno` int(11) NOT NULL, `DepName` varchar(255) DEFAULT NULL, `Remark` varchar(255) DEFAULT NULL, PRIMARY KEY (`Depno`) ) ENGINE=InnoDB DEFAULT CHARSET=gbk; --员工表 CREATE TABLE `employee` ( `Num` int(11) NOT NULL, `Name` varchar(255) DEFAULT NULL, `Addr` varchar(255) DEFAULT NULL, `Zip` varchar(255) DEFAULT NULL, `Tel` varchar(255) DEFAULT NULL, `Email` varchar(255) DEFAULT NULL, `Depno` int(11) DEFAULT NULL, `Birth` date DEFAULT NULL, `Sex` varchar(255) DEFAULT NULL, PRIMARY KEY (`Num`) ) ENGINE=InnoDB DEFAULT CHARSET=gbk; --收支表 CREATE TABLE `salary` ( `Num` int(11) NOT NULL, `InCome` varchar(255) DEFAULT NULL, `OutCome` varchar(255) DEFAULT NULL, PRIMARY KEY (`Num`) ) ENGINE=InnoDB DEFAULT CHARSET=gbk;
查询:
-- （1）查询每个雇员的所有记录； select * from employee; -- （2）查询前5个会员的所有记录； select * from employee limit 5; -- （3）查询每个雇员的地址和电话； select addr,tel from employee; -- （4）查询num为001的雇员地址和电话； select addr,tel from employee where num='1'; -- （5）查询表Employee表中女雇员的地址和电话，使用AS子句将结果列中各列的标题分别指定为地址、电话； select addr as '地址',tel as '电话' from employee where sex='女'; -- （6）计算每个雇员的实际收入； select income-outcome,num from salary; -- （7）找出所有性王的雇员的部门号（部门号不能重复显示）； select depno from employee where name like '王%' group by depno; select distinct depno from employee where name like '王%'; -- （8）找出所有收入在2000－3000元之间的雇员编号 select num from salary where income between 2000 and 3000; -- 练习2：子查询的使用（答案可以不唯一） -- （1）查找在财务部工作的雇员情况； -- 子查询 select * from employee where depno= (select depno from department where DepName='财务部') -- 等值链接 select e.* from employee e,department d where e.depno=d.depno and d.depname='财务部'; -- 内链接，以两个表共有的数据列为基准查询 select e.* from employee e INNER JOIN department d on e.depno=d.depno and d.depname='财务部'; -- exists select e.* from employee e where exists(select d.* from department d where d.depno=e.depno and d.depname='财务部' ); -- （2）查找在财务部且年龄不低于研发部任一个雇员年龄的雇员的姓名； select e1.name from employee e1, department d, (select min(e.birth) bir from employee e right join department d on e.depno=d.depno and d.depname='研发部') e2 where e1.birth < e2.bir and e1.depno=d.depno and d.DepName='财务部' -- （3）查找比所有财务部雇员收入都高的雇员的姓名； select name from employee e1,salary s1 where s1.income> (select max(s.income) from employee e,department d,salary s where e.num = s.num and e.depno=d.depno and d.depname='财务部') and s1.num=e1.num; -- exists select e1.name from employee e1,salary s1 where s1.num=e1.num and not exists (select * from employee e,department d,salary s where e.num = s.num and e.depno=d.depno and d.depname='财务部' and s1.income <= s.income) -- 练习3：连接查询的使用 -- （1）查找每个雇员的情况及薪水情况； select * from employee e,department d,salary s WHERE e.num=s.num and e.depno=d.depno order by e.num; -- （2）查找财务部收入在2200元以上的雇员姓名及其薪水详细情况； select e.name,s.* from employee e,department d,salary s WHERE e.num=s.num and e.depno=d.depno and d.DepName='财务部' and s.InCome>2200; -- -- 练习4：数据汇总 -- （1）求财务部雇员的平均实际收入； select avg(income-outcome) from employee e,department d,salary s where e.num=s.num and e.depno=d.depno and d.depname='财务部' -- （2）求财务部雇员的总人数； select count(e.name) from employee e,department d where d.depno = e.depno and d.depname='财务部' -- 练习5：GROUP BY 、ORDER BY 子句的使用 -- （1）求各部门的雇员数（要求显示，部门号、部门名称和部门雇员数）； select d.Depno,d.DepName,count(name) from employee e,department d where d.Depno=e.Depno group by e.depno; -- 'null' <> null -- （2）求部门的平均薪水大于2500的部门信息（要求显示，部门号、部门名称和平均工资） select d.depno,d.depname,avg(s.income) from employee e,department d,salary s where e.num = s.num and d.depno=e.depno group by d.depno,d.DepName having avg(s.income)>2500
查询练习2-图书借阅管理
建表:
-- ----------------------------
-- Table structure for books
-- ----------------------------
DROP TABLE IF EXISTS `books`;
CREATE TABLE `books` (
`bno` varchar(10) NOT NULL,
`bname` varchar(50) NOT NULL,
`author` varchar(20) NOT NULL,
`price` double(100,0) DEFAULT NULL,
`quantity` int(100) DEFAULT NULL,
PRIMARY KEY (`bno`)
) ENGINE=InnoDB DEFAULT CHARSET=gbk;
-- ----------------------------
-- Records of books
-- ----------------------------
INSERT INTO `books` VALUES ('1001', '九阳真经', '武林', '10000', '2');
INSERT INTO `books` VALUES ('1002', '百花神功', '少林派', '9500', '6');
INSERT INTO `books` VALUES ('1003', '易筋经', '周文王', '9200', '20');
INSERT INTO `books` VALUES ('1004', '葵花宝典', '东方不败', '8880', '0');
INSERT INTO `books` VALUES ('1005', '神照经', '狄云', '7600', '12');
INSERT INTO `books` VALUES ('1006', '九阴真经', '郭襄', '8752', '3');
INSERT INTO `books` VALUES ('1007', '吸星大法', '任千尺', '5212', '2');
INSERT INTO `books` VALUES ('1008', '化功大法', '鬼谷子', '4600', '21');
INSERT INTO `books` VALUES ('1009', '六脉神剑', '段誉', '6325', '6');
INSERT INTO `books` VALUES ('1010', '一阳指', '段正淳', '5300', '11');
-- ----------------------------
-- Table structure for borrows
-- ----------------------------
DROP TABLE IF EXISTS `borrows`;
CREATE TABLE `borrows` (
`no` int(11) NOT NULL AUTO_INCREMENT,
`cno` varchar(10) NOT NULL,
`bno` varchar(10) NOT NULL,
`rdate` datetime DEFAULT NULL,
`jdate` datetime NOT NULL,
PRIMARY KEY (`no`),
KEY `fk_cno` (`cno`),
KEY `fk_bno` (`bno`),
CONSTRAINT `fk_bno` FOREIGN KEY (`bno`) REFERENCES `books` (`bno`),
CONSTRAINT `fk_cno` FOREIGN KEY (`cno`) REFERENCES `card` (`cno`)
) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=gbk;
-- ----------------------------
-- Records of borrows
-- ----------------------------
INSERT INTO `borrows` VALUES ('1', '1002', '1001', '2018-07-30 10:34:23', '2018-07-29 11:19:54');
INSERT INTO `borrows` VALUES ('2', '1002', '1002', '2018-07-30 10:34:41', '2018-06-24 11:20:01');
INSERT INTO `borrows` VALUES ('3', '1002', '1003', '2018-07-30 10:35:00', '2018-06-30 11:20:22');
INSERT INTO `borrows` VALUES ('4', '1002', '1004', '2018-07-30 10:35:13', '2018-07-01 12:00:00');
INSERT INTO `borrows` VALUES ('5', '1002', '1005', '2018-08-01 10:35:33', '2018-07-01 12:00:00');
INSERT INTO `borrows` VALUES ('6', '1002', '1006', '2018-08-01 10:35:54', '2018-07-01 12:00:00');
INSERT INTO `borrows` VALUES ('7', '1002', '1007', '2018-08-03 10:36:13', '2018-07-11 12:00:00');
INSERT INTO `borrows` VALUES ('8', '1003', '1005', '2018-07-17 10:36:33', '2018-06-11 12:00:00');
INSERT INTO `borrows` VALUES ('9', '1006', '1006', '2018-07-02 10:36:54', '2018-06-01 12:00:00');
INSERT INTO `borrows` VALUES ('10', '1005', '1008', '2018-07-12 10:37:24', '2018-07-01 12:00:00');
INSERT INTO `borrows` VALUES ('11', '1007', '1006', '2018-07-17 10:37:42', '2018-06-21 12:00:00');
INSERT INTO `borrows` VALUES ('12', '1009', '1008', '2018-08-07 10:38:00', '2018-07-30 11:22:35');
INSERT INTO `borrows` VALUES ('13', '1004', '1006', '2018-08-17 10:38:16', '2018-07-30 11:23:00');
INSERT INTO `borrows` VALUES ('14', '1004', '1004', '2018-08-07 10:38:31', '2018-07-21 00:00:00');
INSERT INTO `borrows` VALUES ('15', '1005', '1001', '2018-06-30 10:38:50', '2018-06-05 00:00:00');
INSERT INTO `borrows` VALUES ('16', '1009', '1003', '2018-07-29 10:39:09', '2018-06-07 00:12:23');
INSERT INTO `borrows` VALUES ('17', '1009', '1006', null, '2018-07-02 11:24:50');
INSERT INTO `borrows` VALUES ('18', '1006', '1009', null, '2018-05-31 11:25:32');
-- ----------------------------
-- Table structure for card
-- ----------------------------
DROP TABLE IF EXISTS `card`;
CREATE TABLE `card` (
`cno` varchar(10) NOT NULL,
`name` varchar(20) NOT NULL,
`class` varchar(20) DEFAULT NULL,
PRIMARY KEY (`cno`)
) ENGINE=InnoDB DEFAULT CHARSET=gbk;
-- ----------------------------
-- Records of card
-- ----------------------------
INSERT INTO `card` VALUES ('1002', '郭靖', '丐帮');
INSERT INTO `card` VALUES ('1003', '黄蓉', '东邪');
INSERT INTO `card` VALUES ('1004', '杨康', '辽国');
INSERT INTO `card` VALUES ('1005', '穆念慈', '辽国');
INSERT INTO `card` VALUES ('1006', '华筝', '蒙古 ');
INSERT INTO `card` VALUES ('1007', '黄药师', '东邪');
INSERT INTO `card` VALUES ('1008', '欧阳峰', '西毒');
INSERT INTO `card` VALUES ('1009', '一灯大师', '南帝');
INSERT INTO `card` VALUES ('1010', '洪七公', '北丐');
INSERT INTO `card` VALUES ('1011', '柯镇恶', '江南七怪');
INSERT INTO `card` VALUES ('1012', '朱聪', '江南七怪');
INSERT INTO `card` VALUES ('1013', '韩宝驹', '江南七怪');
INSERT INTO `card` VALUES ('1014', '南希仁', '江南七怪');
INSERT INTO `card` VALUES ('1015', '张阿生', '江南七怪');
INSERT INTO `card` VALUES ('1016', '全金发', '江南七怪');
INSERT INTO `card` VALUES ('1017', '韩小莹', '江南七怪');
查询:
-- 2.找出借书超过5本的读者,输出借书卡号及所借图书册数。 select cno,count(cno) from borrows group by cno having count(cno)>5; -- 3.查询借阅了"葵花宝典"一书的读者，输出姓名及班级。 select c.name,c.class from books b,borrows br,card c where br.cno=c.cno and br.bno=b.bno and b.bname='葵花宝典'; -- 4.查询过期未还图书，输出借阅者（卡号）、书号及还书日期。 select * from borrows where rdate<now(); -- 5.查询书名包括"网络"关键词的图书，输出书号、书名、作者。 select * from books where bname like '%真%'; -- 6.查询现有图书中价格最高的图书，输出书名及作者。 select bname,AUTHOR,price from books where price = (select max(price) from books) -- 7.查询当前借了"葵花宝典"但没有借"六脉神剑"的读者，输出其借书卡号，并按卡号降序排序输出。 select c.* from card c,borrows br,books b where c.cno=br.cno AND br.bno=b.bno and b.bname='葵花宝典' and c.cno not in( select c.cno from card c,borrows br,books b where c.cno=br.cno AND br.bno=b.bno and b.bname='六脉神剑') order by c.cno desc; -- 8.将"丐帮"班同学所借图书的还期都延长一周。 update borrows set rdate=ADDDATE(rdate,INTERVAL 7 DAY) where cno in (select cno from card where class='丐帮') -- 9.从BOOKS表中删除当前无人借阅的图书记录。 delete from books WHERE bno not in(select bno from borrows); -- 10.查询当前同时借有"九阴真经"和"葵花宝典"两本书的读者，输出其借书卡号，并按卡号升序排序输出。 select * from card c,borrows br,books b where c.cno=br.cno and br.bno=b.bno and b.bname='九阴真经' and c.cno in( select c.cno from card c,borrows br,books b where c.cno=br.cno and br.bno=b.bno and b.bname='葵花宝典') order by c.cno;