MySQL 启动、连接、创建用户、授权

mysql.start
mysql.stop
mysql.restart
mysql.status

1. 连接
mysql -u root -p;

2. 显示所有数据库
show databases;

3. 使用某个数据库
use engineer;

4. 创建用户
命令:CREATE USER 'username'@'host' IDENTIFIED BY 'password';
create user 'tiger'@'%' identified by 'tiger';

说明:
    username - 用户名
    host - 指定该用户在哪个主机上可以登陆，本地可用localhost, 可以从任意远程主机登陆使用通配符 %.
    password - 该用户的登陆密码，密码为空表示该用户不需要密码登陆服务器.
例子:
    CREATE USER 'dog'@'localhost' IDENTIFIED BY '123456';
    CREATE USER 'pig'@'192.168.1.101' IDENTIFIED BY '123456';
    CREATE USER 'pig'@'%' IDENTIFIED BY '123456';
    CREATE USER 'pig'@'%' IDENTIFIED BY '';
    CREATE USER 'pig'@'%'; 

5. 为用户授权

命令:
    GRANT privileges ON databasename.tablename TO 'username'@'host'
说明:
    privileges - 用户的操作权限，如SELECT，INSERT，UPDATE 等(详细列表见该文最后面)。如果要授予所有的权限则使用ALL.;
    databasename - 数据库名
    tablename - 表名，如果要授予该用户对所有数据库和表的相应操作权限则可用*表示，如 *.*
例子:
    GRANT SELECT, INSERT ON test.user TO 'pig'@'%';
    GRANT ALL ON *.* TO 'pig'@'%';
注意:
    用以上命令授权的用户不能给其它用户授权，如果想让该用户可以授权，用以下命令:
    GRANT privileges ON databasename.tablename TO 'username'@'host' WITH GRANT OPTION; 

6. 撤销权限

命令:
    REVOKE privilege ON databasename.tablename FROM 'username'@'host';
说明:
    privilege，databasename，tablename - 同授权部分.
例子:
    REVOKE SELECT ON *.* FROM 'pig'@'%';
注意:
    假如你在给用户'pig'@'%'授权的时候是这样的(或类似的):
    GRANT SELECT ON test.user TO 'pig'@'%',
    则在使用REVOKE SELECT ON *.* FROM 'pig'@'%';
    命令并不能撤销该用户对test数据库中user表的SELECT 操作.
    相反,如果授权使用的是GRANT SELECT ON *.* TO 'pig'@'%';
    则REVOKE SELECT ON test.user FROM 'pig'@'%';
    命令也不能撤销该用户对test数据库中user表的Select 权限.
    具体信息可以用命令SHOW GRANTS FOR 'pig'@'%'; 查看.
7. 删除用户

命令:
    DROP USER 'username'@'host';

附表:在MySQL中的操作权限

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.