Centos下MySql使用者管理

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1.建立使用者

CREATE USER ‘username‘@‘host‘ IDENTIFIED BY ‘password‘; 

 

2.使用者授權

GRANT privileges ON databasename.tablename TO ‘username‘@‘host‘;

說明: privileges - 使用者的操作許可權,如SELECT , INSERT , UPDATE 等(詳細列表見該文最後面).如果要授予所的許可權則使用ALL.;databasename - 資料庫名,tablename-表名,如果要授予該使用者對所有資料庫和表的相應操作許可權則可用*表示, 如*.*.

例子:

GRANT SELECT, INSERT ON test.user TO ‘pig‘@‘%‘;GRANT ALL ON *.* TO ‘pig‘@‘%‘; 

注意:用以上命令授權的使用者不能給其它使用者授權,如果想讓該使用者可以授權,用以下命令:

GRANT privileges ON databasename.tablename TO ‘username‘@‘host‘ WITH GRANT OPTION;

 

3.取消授權

REVOKE privilege ON databasename.tablename FROM ‘username‘@‘host‘; 

說明: privilege, databasename, tablename - 同授權部分.

例子:

REVOKE SELECT ON *.* FROM ‘pig‘@‘%‘; 

注意: 假如你在給使用者‘pig‘@‘%‘授權的時候是這樣的(或類似的):GRANT SELECT ON test.user TO ‘pig‘@‘%‘, 則在使用REVOKE SELECT ON *.* FROM ‘pig‘@‘%‘;命令並不能撤銷該使用者對test資料庫中user表的SELECT 操作.相反,如果授權使用的是GRANT SELECT ON *.* TO ‘pig‘@‘%‘;則REVOKE SELECT ON test.user FROM ‘pig‘@‘%‘;命令也不能撤銷該使用者對test資料庫中user表的Select 許可權.

具體資訊可以用命令 SHOW GRANTS FOR ‘pig‘@‘%‘;  查看.

 

4.設定或修改密碼

SET PASSWORD FOR ‘username‘@‘host‘ = PASSWORD(‘newpassword‘);

如果是當前登陸使用者用 SET PASSWORD = PASSWORD("newpassword");

例子:

SET PASSWORD FOR ‘pig‘@‘%‘ = PASSWORD("123456");

如果忘記root密碼，操作如下：

1).linux切換到root使用者

2).修改MySql的登陸設定，編輯my.cnf檔案

　　 [[email protected] /]# vi /etc/my.cnf 

　　在[mysqld]欄位下加入一句： skip-grant-tables

　　儲存退出。

3).重新啟動mysqld

　　 [[email protected] /]# service mysqld restart 

4).之後可以免密碼進入MySql，然後use mysql

[[email protected] /]# mysqlWelcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 3Server version: 5.7.18 MySQL Community Server (GPL)Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.mysql> use mysql;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changed

5).修改root使用者密碼

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

6).退出MySql，編輯my.cnf，刪除skip-grant-tables一行

7).可用root使用者的新密碼登進MySql

 

5.刪除使用者

DROP USER ‘username‘@‘host‘; 

 

 

 

附表：在MySql中的操作許可權

 

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.

 

Centos下MySql使用者管理