1. Mysql 5.7 在自動初始化數據庫的時候，會生成root用戶的默認密碼。mysql
經過 grep "temporary password" /var/log/mysqld.log 命令，返回結果最後冒號後面的字符串就是root的默認密碼。sql
使用此密碼登陸後，Mysql 會要求第一件作的事就是改root密碼，並且是要求強密碼。能夠經過set password=password('密碼')來更改。數據庫
2. 沒法找到密碼,忘記設置的是啥了centos
在/etc/my.cnf 中添加 skip-grant-tables 參數。此參數的做用是登陸Mysql 數據庫不進行用戶密碼驗證。ide
修改後, 重啓服務 systemctl restart mysqld.
[root@VM_0_15_centos ~]# service mysqld restart Stopping mysqld: [ OK ] Starting mysqld: [ OK ] [root@VM_0_15_centos ~]# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 Server version: 5.7.26 MySQL Community Server (GPL) Copyright (c) 2000, 2019, 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> update mysql.user set authentication_string=password('123456pswd') where user='root' and Host = 'localhost'; Query OK, 1 row affected, 1 warning (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 1 mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) mysql> quit Bye
# 將/etc/my.cnf 中 skip-grant-tables 註釋,重啓服務
[root@VM_0_15_centos ~]# mysql -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 Server version: 5.7.26 Copyright (c) 2000, 2019, 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>
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.測試
設置一個簡單的測試密碼的話，如123456，會提示這個錯誤.ui
mysql> alter user 'root'@'localhost' identified by 'password';this
或者 mysql> set password=password("password");spa
mysql> show databases; ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement. mysql> alter user 'root'@'localhost' identified by '123456pswd'; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | ops | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) mysql> quit Bye