Mysql new user and delete user specific operation command _ MySQL

Method 1: Using mysqlroot (root permission) user login direct authorization can also create a user usrbinmysqladmin-urootpassword123456mysql-uroot-p password to view all user names and passwords selecthost, user, passwordf Method 1: using mysql root (root permission) you can directly grant permissions when logging on to a user or create a user.
/Usr/bin/mysqladmin-u root password 123456


Mysql-uroot-p
Password
View all user names and passwords
Select host, user, password from user;

Grant all on ec. * to 'root' @ '%' identified by '123 ';
Grant all privileges on ec. * to 'cockpit' @ '% 'identified by '123 ';
Grant all on ec. * to 'cockpit' @ '%' identified by '123 ';
Grant all privileges on ec. * to 'cockpit' @ '% 'identified by '123 ';
Flush privileges ;;

Change database password
User mysql

Modify the password of a mysql database
UPDATE user SET Password = PASSWORD ('000000') where USER = 'root ';
Mysql root password is empty. No password is required for login.
UPDATE user SET Password = PASSWORD (null) where USER = 'root ';
Flush privileges;

Method 2:
1. create a user.
// Log on to MYSQL
@> Mysql-u root-p
@> Password
// Create a database (testDB) for the user first)
Mysql> create database testDB default character set utf8 ;;
// Create a user
Mysql> insert into mysql. user (Host, User, Password) values ("localhost", "test", password ("1234 "));
// Refresh the system permission list
Mysql> flush privileges;
In this way, a user named: test password: 1234 is created.
Then log on.
Mysql> exit;
@> Mysql-u phplamp-p
@> Enter the password
Mysql> logon successful
2. authorize the user.
Format: grant permission on database. * to username @ login host identified by "password ";
> Grant all privileges on phplampDB. * to phplamp @ localhost identified by '100 ";

Authorize the test user to have certain permissions on all databases:
Mysql> grant select, delete, update, create, drop on *. * to test @ "%" identified by "1234 ";

// The test user has the select, delete, update, create, and drop permissions on all databases.

// @ "%" Indicates authorizing all non-local hosts, excluding localhost. (The localhost address is set to 127.0.0.1. if it is set to a real local address, you do not know if it is OK. No verification is performed .)

// Authorize localhost: add the grant all privileges on testDB. * to test @ localhost identified by '20140901.

3. delete a user.
@> Mysql-u root-p
@> Password
Mysql> delete from user WHERE User = "test" and Host = "localhost ";
Mysql> flush privileges;
// Delete the user's database
Mysql> drop database testDB;
4. modify the password of the specified user.
@> Mysql-u root-p
@> Password
Mysql> update mysql. user set password = password ('New password') where User = "test" and Host = "localhost ";
Mysql> flush privileges;

Delete from user where User = "test" and Host = "localhost ";

You can also try:

Delete Account and permissions:> drop user username @ '% ';

> Drop user username @ localhost;