MySQL建立user表：
CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) DEFAULT NULL,
  `password` varchar(32) DEFAULT NULL,
  `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `phone` varchar(11) NOT NULL,
  `email` varchar(32) NOT NULL,
  `type` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
)
user表增加一個性別字段
alter table user add sex varchar(10) not null;

修改性別欄位為年齡
alter table user change sex age int(4) not null;

刪除年齡欄位
alter table user drop COLUMN age

查詢資料
select * from user

select name,phone,email from user

select name,phone,email from user where name='張三'

select name,phone,email from user where name like '%張%'//模糊查詢，查詢名字裡帶“張”的

增加記錄

insert into user（name,phone,email）values('sun','17798746531','

修改資料

update user set name='timy' where id=9

刪除資料

delete from user where name = 'timy'