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[数据库]MySQL创建和操作数据库表demo


【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------添加字段

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------修改字段名

 mysql> ALTER TABLE workers_info CHANGE email mailbox varchar(30);

【6】向表里添加10条记录------添加数据

mysql> INSERT INTO workers_info (workername,salary,tel,mailbox,department,qq,EmployedDates) values('xing',10000,'1598232123','xing@qq.com','yanfa',736019646,20121221);

【7】修改其中两条记录的tel和mailbox------修改数据

mysql> UPDATE workers_info SET mailbox = 'haha@qq.com',tel='1246543423' WHERE id = 13;

【8】查看所添加记录------查询数据

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------日期筛选

mysql> select * from workers_info where year(EmployedDates) < 2003;

【11】查询工资最高和最低的员工姓名------排序

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------平均函数

mysql> select avg(salary) from workers_info;

【13】统计男员工人数、女员工人数------总和函数

mysql> select count(1) from workers_info where sex="M";

【14】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;

 

版权出自:http://blog.csdn.net/kakane/article/details/7401111