create database if not exists wsp_test  default charset utf8 collate utf8_general_ci

use wsp_test;

source sql文件路径

create table if not exists user (

    user_id INT() NOT NULL AUTO_INCREMENT,

    name varchar() default NULL,

    create_time date default NULL,

    primary key (user_id)

 );

注意点：

    默认值是否非空

    表类型

    主键

    自增

常用表字段类型：

    int

    char

    varchar

    datetime

    double

参考链接：mysql数据类型

修改表字段数据类型

alter table wsp_test change column user_id id int() not null auto_increment;

增加列

alter table user add column descss varchar() default null;

删除列

alter table user drop column descss;

重命名表

alter table user rename to users;

清空表

truncate table users;

insert into users(name) values("小名");

insert into users(name) values("小红");

insert into users(name) values("小白");

insert into users(name) values("小青");

insert into users(name) values("小紫");

update users set name = '小黄' where name = '小白';

update users,salary set salary = salary + salary*percent where salary =   ## 连表更新

delete from salary where salary = ;

delete users,salary from users inner join salary on users.id = salary.user_id  where salary.salary = ; ## 多表删除