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在[mysqld]的段中加上一句

skip-grant-tables 

 service mysqld restart

mysql> use mysqlReading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> update mysql.user set authentication_string=password('****') where user='root';Query OK, 0 rows affected, 1 warning (0.00 sec)Rows matched: 2Changed: 0Warnings: 1mysql> exit

 步骤1 中，在配置文件中新增的部分，删除；

 service mysqld restart

Enter password:
Welcome to the MySQL monitor.Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.15 MySQL Community Server (GPL)

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Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> GRANT ALL PRIVILEGES ON*.* TO 'root'@'%' IDENTIFIED BY 'your root password' WITH GRANT OPTION;Query OK, 0 rows affected, 1 warning (0.00 sec)mysql> flush privileges;Query OK, 0 rows affected (0.00 sec)