1、打開終端，輸入命令：cd /usr/local/mysql/bin
2、mysql -uroot -p，用這條命令登陸時報錯信息：
報錯：Enter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
3、打開終端輸入：sudo mysqld_safe --skip-grant-tables
輸出 Password: Logging to '/usr/local/mysql/data/localhost.err'. 2018-10-10T03:21:40.6NZ mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data
4、打開一個新的終端，輸入：mysql -u root ，會看到以下輸出。
Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 16 Server version: 5.7.23 MySQL Community Server (GPL) Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
5、終端輸入 use mysql顯示如下
Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed
6、修改密碼：UPDATE mysql.user SET authentication_string=PASSWORD('你的密碼') WHERE User='root';
Query OK, 1 row affected, 1 warning (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 1