MySQL foundation 07-dcl

DCL sentence

DCL Statements are mainly DBA Used to manage object permissions in the system , Common developers rarely use . below
Let's briefly explain it with an example .
Create a database user plf, Have right plf Of all the tables in the database SELECT/INSERT jurisdiction ：

1. Manage users

1.  Add users ：
    *  grammar ：CREATE USER ' user name '@' Host name ' IDENTIFIED BY ' password ';
    *  The host name can be used % Indicates that the user can access the database from any address 
2.  Delete user ：
    *  grammar ：DROP USER ' user name '@' Host name ';
3.  Change user password ：
    UPDATE USER SET PASSWORD = PASSWORD(' New password ') WHERE USER = ' user name ';
    UPDATE USER SET PASSWORD = PASSWORD('abc') WHERE USER = 'lisi';

    SET PASSWORD FOR ' user name '@' Host name ' = PASSWORD(' New password ');
    SET PASSWORD FOR 'root'@'localhost' = PASSWORD('123');

    * mysql I forgot root User's password ？
        1. cmd -- > net stop mysql  stop it mysql service 
            *  The administrator is required to run the cmd
        2.  Start with no validation mysql service ： mysqld --skip-grant-tables
        3.  Open up new cmd window , Direct input mysql command , Knock back . You can log in successfully 
        4. use mysql;
        5. update user set password = password(' Your new password ') where user = 'root';
        6.  Close two windows 
        7.  Open Task Manager , Manual end mysqld.exe  The process of 
        8.  start-up mysql service 
        9.  Log in with the new password .
4.  Query the user ：
    -- 1.  Switch to mysql database 
    USE myql;
    -- 2.  Inquire about user surface 
    SELECT * FROM USER;

 notes ： wildcard ： %  Indicates that the user can log in to the database on any host 

2. Rights management ：

1.  Query authority ：
    --  Query authority 
    SHOW GRANTS FOR ' user name '@' Host name ';
    SHOW GRANTS FOR 'lisi'@'%';

2.  Grant authority ：
    --  Grant authority 
    grant  Permission list  on  Database name . Table name  to ' user name '@' Host name ';
    --  Give all permissions to Zhang San , On any table in any database 
    GRANT ALL ON *.* TO 'zhangsan'@'localhost';
3.  Revoke authority ：
    --  Revoke authority ：
    revoke  Permission list  on  Database name . Table name  from ' user name '@' Host name ';
    REVOKE UPDATE ON db3.`account` FROM 'lisi'@'%';