mysql學習之-密碼管理（默認密碼，修改密碼，解決忘記密碼）
1.
mysql安裝后默認沒有密碼，初始化安裝后默認密碼登錄，需要馬上修改root密碼。
[root@mysql ~]# cat /root/.mysql_secret --查看root賬號密碼
# The random password set for the root user at Tue Dec 13 18:59:06 2016 (local time): 7MhtyX3aZEl9OUf8
[root@mysql ~]# mysql -uroot -p -- 登錄mysql
Enter password: --（此處復制粘貼 7MhtyX3aZEl9OUf8）
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.25
Copyright (c) 2000, 2015, 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.
說明： 出現mysql> 表示一切順利成功。
2. 修改密碼
mysql> SET PASSWORD = PASSWORD('123456'); --設置密碼為123456
[root@mysql etc]# mysql -uroot -p123456 --修改密碼后，登錄
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 39
Server version: 5.6.25 MySQL Community Server (GPL)
mysql> --登錄成功
3. 忘記mysql數據庫root的密碼后，如何修改密碼。
[root@mysql etc]# service mysql stop --停止mysql進程
Shutting down MySQL.... SUCCESS!
[root@mysql etc]# mysqld_safe --skip-grant-tables& --啟動mysql時不啟動grant-tables，授權表。執行后出現下面畫面，另起一個新會話。
[1] 3574
[root@mysql etc]# 161215 06:13:53 mysqld_safe Logging to '/var/lib/mysql/mysql.err'.
161215 06:13:53 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
[root@mysql ~]# ps -ef|grep mysql --查看mysql進程是否起來
root 3467 3440 0 05:29 pts/2 00:00:00 mysql -uandy -px xx
root 3574 2845 0 06:13 pts/0 00:00:00 /bin/sh /usr/bin/mysqld_safe --skip-grant-tables
mysql 3677 3574 2 06:13 pts/0 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-
mysql> UPDATE user SET password=PASSWORD('cccccc') WHERE user='root'; --更改root密碼
Query OK, 4 rows affected (0.04 sec)
Rows matched: 4 Changed: 4 Warnings: 0
mysql> FLUSH PRIVILEGES; --權限更新
Query OK, 0 rows affected (0.00 sec)
[root@mysql ~]# mysql -uroot -p123456 --使用舊密碼登錄，發現不行，說明密碼已經更新
Warning: Using a password on the command line interface can be insecure.
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
[root@mysql ~]# mysql -uroot -pcccccc --新密碼登錄成功
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
mysql>
