http://blog.csdn.net/kakane/article/details/7401111
【1】建立员工档案表
要求字段:员工员工编号,员工姓名,性别,工资,email,入职时间,部门。
【2】合理选择数据类型及字段修饰符,要求有NOT NULL,auto_increment, primary key等。
DROP TABLE IF EXISTS `workers_info`; CREATE TABLE `workers_info` ( `id` int(11) NOT NULL AUTO_INCREMENT, `workername` varchar(20) NOT NULL, `sex` enum(F,M,S), `salary` int(11) DEFAULT '0', `email` varchar(30), `EmployedDates` date, `department` varchar(30), PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; mysql> alter table workers_info ADD sex enum('F','M','S');
【3】查看表的结构
mysql> desc workers_info;
【4】新增qq和tel字段,要求tel字段位于email前,要求入职时间是最后一个字段
mysql> ALTER TABLE workers_info ADD tel varchar(15) after salary;
mysql> ALTER TABLE workers_info ADD qq int; ALTER TABLE workers_info MODIFY EmployedDates date after qq;
【5】把email字段修改成mailbox
ALTER TABLE workers_info CHANGE email mailbox varchar(30);
【6】向表里添加10条记录
mysql> INSERT INTO workers_info (workername,salary,tel,mailbox,department,qq,EmployedDates) values('xing',10000,'1598232123','[email protected]','yanfa',736019646,20121221);
【7】修改其中两条记录的tel和mailbox
mysql> UPDATE workers_info SET mailbox = '[email protected]',tel='1246543423' WHERE id = 13;
【8】查看所添加记录
mysql> select * from workers_info;
【9】查看姓名和入职时间记录
mysql> select workername,EmployedDates from workers_info;
【10】查询入职时间在2003年以前的
mysql> select * from workers_info where year(EmployedDates) < 2003;
【11】查询工资最高和最低的员工姓名
mysql> select * from workers_info ORDER BY salary limit 1;
mysql> select * from workers_info ORDER BY salary desc limit 1;
【12】查询平均工资
mysql> select avg(salary) from workers_info;
【13】统计男员工人数、女员工人数
mysql> select count(男) from workers_info where sex="M"; mysql> select count(女) from workers_info where sex="W";
【14】把email字段长度修改为255
mysql> ALTER TABLE workers_info MODIFY COLUMN email varchar(255);
【15】按照入职时间先后进行排序,并显示前5位员工姓名
mysql> select * from workers_info ORDER BY EmployedDates limit 5;