Mysql基础

Mysql数据类型

字符类型

字符串类型指CHAR、VARCHAR、BINARY、VARBINARY、BLOB、TEXT、ENUM和SET

类型	大小	用途
CHAR	0-255字节	定长字符串
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途
类型	大小	用途

Mysql创建用户与授权

1. 创建用户

mysql> CREATE USER 'mike'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.00 sec)

2. 授权
   命令:GRANT privileges ON databasename.tablename TO 'username'@'host'

grant all PRIVILEGES on *.* to root@'%' identified by '123456'; 

权限名称	说明
ALTER	Allows use of ALTER TABLE
ALTER ROUTINE	Alters or drops stored routines
CREATE	Allows use of CREATE TABLE
CREATE ROUTINE	Creates stored routines
CREATE TEMPORARY TABLE	Allows use of CREATE TEMPORARY TABLE
CREATE USER	Allows use of CREATE USER DROP USER RENAME USER and REVOKE ALL PRIVILEGES
CREATE VIEW	Allows use of CREATE VIEW
DELETE	Allows use of DELETE
DROP	Allows use of DROP TABLE
EXECUTE	Allows the user to run stored routines.
FILE	Allows use of SELECT ... INTO OUTFILE and LOAD DATA INFILE >.
INDEX	Allows use of CREATE INDEX and DROP INDEX
INSERT	Allows use of INSERT
LOCK TABLES	Allows use of LOCK TABLES on tables for which the user also has SELECT privileges
PROCESS	Allows use of SHOW FULL PROCESSLIST
RELOAD	Allows use of FLUSH
REPLICATION	Allows the user to ask where slave or master
CLIENT	servers are
REPLICATION SLAVE	Needed for replication slaves
SELECT	Allows use of SELECT
SHOW DATABASES	Allows use of SHOW DATABASES
SHOW VIEW	Allows use of SHOW CREATE VIEW
SHUTDOWN	Allows use of mysqladmin shutdown
SUPER	Allows use of CHANGE MASTER , KILL , PURGE MASTER LOGS , and SET GLOBAL SQL statements. Allows mysqladmin debug command. Allows one extra connection to be made if maximum connections are reached.
UPDATE	Allows use of UPDATE
USAGE	Allows connection without any specific privileges.

3. 设置与更改用户密码
   命令:SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');如果是当前登陆用户用SET PASSWORD = PASSWORD("newpassword");
   修改当前登录用户的密码

SET PASSWORD = PASSWORD("newpassword"); 

root用户修改其他用户密码 貌似这种方式会报一个警告

mysql> update mysql.user set authentication_string=password("222222") where User="mike" and Host="localhost";
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1

4. 删除用户与权限

drop user 用户名@’%’; 
drop user 用户名@ localhost;

5. mysql 查看状态 开启 关闭

查看是否已开启

ubuntu@VM-0-10-ubuntu:~$ ps -ef|grep mysqld
mysql    25240     1  0 14:21 ?        00:00:02 /usr/sbin/mysqld
ubuntu   30182 28796  0 16:07 pts/0    00:00:00 grep --color=auto mysqld

开启

ubuntu@VM-0-10-ubuntu:~$ service mysql start

关闭

ubuntu@VM-0-10-ubuntu:~$ service mysql stop