MySql命令集锦

drop database if exists db_ name;

create database db_name;

select user from mysql.user;

#create user '用户名‘@'用户登录ip % 表示无限制也可以是localhost' identified by  '密码’

create user 'mxc'@'localhost' identified by 'mxc';

#show grants for 用户名@'IP地址';

show grants for mxc@'localhost';

#mxc用户拥有test数据库的所有权限

grant all on test.* to mxc@localhost identified by 'mxc';

drop table if exists table_name;

create table employee(
	id int auto_increment primary key,
	name varchar(50) not null,
	age int default 18,
	sex int default 0,
	dept int not null)
	default charset =utf8;

desc table_name;

insert into table_name values(对应的列的值）；

alter table 表名 add constraint 外键名字 foreign key(外键字段名） references 外表(对应表的字段);

# 为 employee 添加外键  employee表的dept字段对应dept表里的 d_id字段
alter table employee add constraint FK_ED foreign key(dept) references dept(d_id);

show create table 表名;

alter table 表名 add 列名 数据类型;
# 为 dept表增加 d_location列
alter table dept add d_location varchar(200);