今天访问数据库提示密码错误：
[root@node ~]# mysql -uroot -hlocalhost -p Enter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) [root@node ~]# mysql -uroot -hlocalhost -p Enter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) [root@node ~]#
思来想去，一直想不起密码，最后只有关闭数据库通过添加参数"--skip-grant-tables"来重启启动：
[root@node ~]# /usr/local/mysql/bin/mysqld_safe --defaults-file=/etc/my.cnf --skip-grant-tables & [1] 14254 [root@node ~]# 2018-05-06T07:54:11.083543Z mysqld_safe Logging to '/data/mysql/error.log'. 2018-05-06T07:54:11.107761Z mysqld_safe Starting mysqld daemon with databases from /data/mysql [root@node ~]# ps axu|grep mysql root 14254 0.5 0.0 113252 1648 pts/0 S 15:54 0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/etc/my.cnf --skip-grant-tables mysql 15564 1.9 14.5 2265704 272520 pts/0 Sl 15:54 0:00 /usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --basedir=/usr/local/mysql --datadir=/data/mysql --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --skip-grant-tables --log-error=/data/mysql/error.log --open-files-limit=65535 --pid-file=node.pid --socket=/tmp/mysql.sock --port=3306 root 15606 0.0 0.0 112644 948 pts/0 S+ 15:54 0:00 grep --color=auto mysql [root@node ~]#
重启MySQL服务后，就开始着手修改密码：
1 [root@node ~]# mysql 2 Welcome to the MySQL monitor. Commands end with ; or g. 3 Your MySQL connection id is 2 4 Server version: 5.7.22-log MySQL Community Server (GPL) 5 6 Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. 7 8 Oracle is a registered trademark of Oracle Corporation and/or its 9 affiliates. Other names may be trademarks of their respective 10 owners. 11 12 Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. 13 14 root@db 15:56: [(none)]> use mysql; 15 Database changed 16 root@db 15:56: [mysql]> update user set password=password('root@123') where user='root'; 17 ERROR 1054 (42S22): Unknown column 'password' in 'field list' 18 root@db 15:57: [mysql]>
奇怪了，难道我记错了，后来再一次执行该命令，发现仍然爆出同样的错误，user表中居然没有password这个字段，看了下MySQL版本：5.7.22看来跟5.5 5.6有些不同，进一步查看user表结构：
1 root@db 15:57: [mysql]> desc user; 2 +------------------------+-----------------------------------+------+-----+-----------------------+-------+ 3 | Field | Type | Null | Key | Default | Extra | 4 +------------------------+-----------------------------------+------+-----+-----------------------+-------+ 5 | Host | char(60) | NO | PRI | | | 6 | User | char(32) | NO | PRI | | | 7 | Select_priv | enum('N','Y') | NO | | N | | 8 | Insert_priv | enum('N','Y') | NO | | N | | 9 | Update_priv | enum('N','Y') | NO | | N | | 10 | Delete_priv | enum('N','Y') | NO | | N | | 11 | Create_priv | enum('N','Y') | NO | | N | | 12 | Drop_priv | enum('N','Y') | NO | | N | | 13 | Reload_priv | enum('N','Y') | NO | | N | | 14 | Shutdown_priv | enum('N','Y') | NO | | N | | 15 | Process_priv | enum('N','Y') | NO | | N | | 16 | File_priv | enum('N','Y') | NO | | N | | 17 | Grant_priv | enum('N','Y') | NO | | N | | 18 | References_priv | enum('N','Y') | NO | | N | | 19 | Index_priv | enum('N','Y') | NO | | N | | 20 | Alter_priv | enum('N','Y') | NO | | N | | 21 | Show_db_priv | enum('N','Y') | NO | | N | | 22 | Super_priv | enum('N','Y') | NO | | N | | 23 | Create_tmp_table_priv | enum('N','Y') | NO | | N | | 24 | Lock_tables_priv | enum('N','Y') | NO | | N | | 25 | Execute_priv | enum('N','Y') | NO | | N | | 26 | Repl_slave_priv | enum('N','Y') | NO | | N | | 27 | Repl_client_priv | enum('N','Y') | NO | | N | | 28 | Create_view_priv | enum('N','Y') | NO | | N | | 29 | Show_view_priv | enum('N','Y') | NO | | N | | 30 | Create_routine_priv | enum('N','Y') | NO | | N | | 31 | Alter_routine_priv | enum('N','Y') | NO | | N | | 32 | Create_user_priv | enum('N','Y') | NO | | N | | 33 | Event_priv | enum('N','Y') | NO | | N | | 34 | Trigger_priv | enum('N','Y') | NO | | N | | 35 | Create_tablespace_priv | enum('N','Y') | NO | | N | | 36 | ssl_type | enum('','ANY','X509','SPECIFIED') | NO | | | | 37 | ssl_cipher | blob | NO | | NULL | | 38 | x509_issuer | blob | NO | | NULL | | 39 | x509_subject | blob | NO | | NULL | | 40 | max_questions | int(11) unsigned | NO | | 0 | | 41 | max_updates | int(11) unsigned | NO | | 0 | | 42 | max_connections | int(11) unsigned | NO | | 0 | | 43 | max_user_connections | int(11) unsigned | NO | | 0 | | 44 | plugin | char(64) | NO | | mysql_native_password | | 45 | authentication_string | text | YES | | NULL | | 46 | password_expired | enum('N','Y') | NO | | N | | 47 | password_last_changed | timestamp | YES | | NULL | | 48 | password_lifetime | smallint(5) unsigned | YES | | NULL | | 49 | account_locked | enum('N','Y') | NO | | N | | 50 +------------------------+-----------------------------------+------+-----+-----------------------+-------+ 51 45 rows in set (0.00 sec) 52 53 root@db 16:01: [mysql]>
确实没看到password名字的字段，但是发现一个可疑字段"authentication_string",于是尝试用该字段再执行修改操作：
1 root@db 16:03: [mysql]> use mysql; 2 Database changed 3 root@db 16:03: [mysql]> update user set authentication_string=password('root@123') where user='root'; 4 Query OK, 0 rows affected, 1 warning (0.00 sec) 5 Rows matched: 1 Changed: 0 Warnings: 1 6 7 root@db 16:04: [mysql]> flush privileges; 8 Query OK, 0 rows affected (0.39 sec) 9 10 root@db 16:04: [mysql]> exit 11 Bye
居然可以了，进一步登陆了认证：
1 [root@node ~]# mysql -uroot -hlocalhost -proot@123 2 mysql: [Warning] Using a password on the command line interface can be insecure. 3 Welcome to the MySQL monitor. Commands end with ; or g. 4 Your MySQL connection id is 3 5 Server version: 5.7.22-log MySQL Community Server (GPL) 6 7 Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. 8 9 Oracle is a registered trademark of Oracle Corporation and/or its 10 affiliates. Other names may be trademarks of their respective 11 owners. 12 13 Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. 14 15 root@db 16:04: [(none)]> show databases; 16 +--------------------+ 17 | Database | 18 +--------------------+ 19 | information_schema | 20 | mysql | 21 | performance_schema | 22 | sys | 23 +--------------------+ 24 4 rows in set (0.00 sec) 25 26 root@db 16:05: [(none)]>
看来MySQL5.7跟MySQL5.6 MySQL 5.5在密码修改方面也做了改动，作为笔记仅此而已
如果新安装的MySQL5.7.x 是不允许直接登录：
1 [root@node bin]# pwd 2 /usr/local/mysql/bin 3 [root@node bin]# 4 [root@node bin]# ./mysqld --defaults-file=/etc/my.cnf --datadir=/data/mysql/ --basedir=/usr/local/mysql --user=mysql --initialize 5 [root@node bin]# 6 [root@node bin]# 7 [root@node bin]# ./mysqld_safe --defaults-file=/etc/my.cnf & 8 [1] 19041 9 [root@node bin]# 2018-05-25T21:21:30.360117Z mysqld_safe Logging to '/data/mysql/error.log'. 10 2018-05-25T21:21:30.425323Z mysqld_safe Starting mysqld daemon with databases from /data/mysql 11 12 [root@node bin]# 13 [root@node mysql]# ps xua|grep mysql 14 root 19041 0.6 0.0 113252 1660 pts/0 S 05:21 0:00 /bin/sh ./mysqld_safe --defaults-file=/etc/my.cnf 15 mysql 20336 2.2 14.0 2332432 262536 pts/0 Sl 05:21 0:00 /usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --basedir=/usr/local/mysql --datadir=/data/mysql --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/data/mysql/error.log --open-files-limit=65535 --pid-file=node.pid --socket=/tmp/mysql.sock --port=3306 16 root 20387 0.0 0.0 112644 952 pts/1 S+ 05:21 0:00 grep --color=auto mysql 17 [root@node mysql]# 18 19 [root@node bin]# ./mysql 20 ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO) 21 [root@node bin]# ./mysql -uroot -hlocalhost 22 ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO) 23 [root@node bin]#
从这里发现MySQL5.7.x已经对访问权限做了限制，从前面的提示中可以发现初始密码在error.log中
1 [root@node bin]# grep password /data/mysql/error.log 2 2018-05-25T21:21:07.429395Z 1 [Note] A temporary password is generated for root@localhost: U7zvi&##Ti<A 3 2018-05-25T21:25:10.090750Z 2 [Note] Access denied for user 'root'@'localhost' (using password: NO) 4 2018-05-25T21:25:17.410963Z 3 [Note] Access denied for user 'root'@'localhost' (using password: NO) 5 [root@node bin]#
所以这里可以用该密码就行登录：
1 [root@node bin]# mysql: [Warning] Using a password on the command line interface can be insecure. 2 ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) 3 4 [2]+ Exit 1 ./mysql -uroot -hlocalhost -pU7zvi 5 [root@node bin]# ./mysql -uroot -hlocalhost -p 6 Enter password: 7 Welcome to the MySQL monitor. Commands end with ; or g. 8 Your MySQL connection id is 5 9 Server version: 5.7.22-log 10 11 Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. 12 13 Oracle is a registered trademark of Oracle Corporation and/or its 14 affiliates. Other names may be trademarks of their respective 15 owners. 16 17 Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. 18 19 root@db 05:27: [(none)]> show databases; 20 ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement. 21 root@db 05:27: [(none)]>
发现初始密码可以登录，但是不能操作数据库，比如show databases命令，所以修改初始密码：
1 root@db 05:27: [(none)]> show databases; 2 ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement. 3 root@db 05:27: [(none)]> set PASSWORD='root@123'; 4 Query OK, 0 rows affected (0.00 sec) 5 6 root@db 05:29: [(none)]> flush privileges; 7 Query OK, 0 rows affected (0.01 sec) 8 9 root@db 05:29: [(none)]> 10 root@db 05:29: [(none)]> show databases; 11 +--------------------+ 12 | Database | 13 +--------------------+ 14 | information_schema | 15 | mysql | 16 | performance_schema | 17 | sys | 18 +--------------------+ 19 4 rows in set (0.00 sec) 20 21 root@db 05:29: [(none)]>
所以对于MySQL5.7.x安装后必须修改密码然后才能进行其他操作，另外初始密码是保存在错误日志中。