匿名通过本文主要向大家介绍了mysql，密码遗忘，登陆报错等相关知识,希望本文的分享对您有所帮助
下面小编就为大家带来一篇浅谈mysql密码遗忘和登陆报错的问题。小编觉得挺不错的，现在就分享给大家，也给大家做个参考。一起跟随小编过来看看吧
mysql登录密码忘记，其实解决办法很简单，只需要在mysql的主配置文件my.cnf里添加一行“跳过授权表”的参数选择即可！
在my.cnf中添加下面一行：
[root@test-huanqiu ~]# vim /etc/my.cnf
//在[mysqld]区域里添加
........
skip-grant-tables
//跳过授权表然后重启mysql服务，即可无密码登录
[root@test-huanqiu ~]# /etc/init.d/mysqld restart
登录后重置密码
[root@test-huanqiu ~]# mysql
mysql> select host,user,password from mysql.user;
+--------------------+------+-------------------------------------------+
| host | user | password |
+--------------------+------+-------------------------------------------+
| localhost | root | *481ACA1BD6D1E86221244904E9C0FABA33B40B84 |
| host-192-168-1-117 | root | |
| 127.0.0.1 | root | |
| ::1 | root | |
| localhost | | |
| host-192-168-1-117 | | |
+--------------------+------+-------------------------------------------+
6 rows in set (0.00 sec)
mysql> update mysql.user set password=password("123456") where host="localhost" and user="root";
Query OK, 1 row affected (0.02 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
mysql> select host,user,password from mysql.user;
+--------------------+------+-------------------------------------------+
| host | user | password |
+--------------------+------+-------------------------------------------+
| localhost | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
| host-192-168-1-117 | root | |
| 127.0.0.1 | root | |
| ::1 | root | |
| localhost | | |
| host-192-168-1-117 | | |
+--------------------+------+-------------------------------------------+
6 rows in set (0.00 sec)
mysql>再次将my.cnf里添加的那一行注释，然后重启mysql
[root@test-huanqiu ~]# vim /etc/my.cnf........#skip-grant-tables [root@test-huanqiu ~]# /etc/init.d/mysqld restart [root@test-huanqiu ~]# mysql -p123456mysql>
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发现的一个坑：
mysql之前进行了全量备份，在恢复后，发现用之前的密码登陆不进去了！
使用上面的方法，无密码登陆后再重置密码，但是重置密码后发现仍然登陆不进去。
最后发现是因为mysql.user表内容被清空了！
mysql> select host,user,password from user; Empty set (0.00 sec)
解决：
插入数据，再重置密码
mysql> insert into user(host,user,password) values("localhost","root","123456");
Query OK, 1 row affected, 3 warnings (0.01 sec)
mysql> select host,user,password from user;
+-----------+------+----------+
| host | user | password |
+-----------+------+----------+
| localhost | root | 123456 |
+-----------+------+----------+
1 row in set (0.00 sec)
mysql> update mysql.user set password=password("123456") where host="localhost" and user="root";
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select host,user,password from user;
+-----------+------+-------------------------------------------+
| host | user | password |
+-----------+------+-------------------------------------------+
| localhost | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-----------+------+-------------------------------------------+
1 row in set (0.00 sec)
mysql> insert into user(host,user,password) values("127.0.0.1","root","123456");
Query OK, 1 row affected, 3 warnings (0.00 sec)
mysql> select host,user,password from user;
+-----------+------+-------------------------------------------+
| host | user | password |
+-----------+------+-------------------------------------------+
| localhost | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
| 127.0.0.1 | root | 123456 |
+-----------+------+-------------------------------------------+
2 rows in set (0.00 sec)
mysql> update mysql.user set password=password("123456") where user="root";
Query OK, 1 row affected (0.00 sec)
Rows matched: 2 Changed: 1 Warnings: 0
mysql> select host,user,password from user;
+-----------+------+-------------------------------------------+
| host | user | password |
+-----------+------+-------------------------------------------+
| localhost | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
| 127.0.0.1 | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-----------+------+-------------------------------------------+然后使用重置后的密码就能正常登陆了！
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mysql登录报错1：
[root@test-huanqiu ~]# mysql -p123456ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (111) [root@test-huanqiu ~]# ps -ef|grep mysqlroot 28279 1 0 12:55 ? 00:00:00 /bin/sh /usr/local/mysql//bin/mysqld_safe --datadir=/data/mysql/data --pid-file=/data/mysql/data/mysql.pidmysql 29059 28279 0 12:55 ? 00:00:01 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql/ --datadir=/data/mysql/data --plugin-dir=/usr/local/mysql//lib/plugin --user=mysql --log-error=/data/mysql/data/mysql-error.log --pid-file=/data/mysql/data/mysql.pid --socket=/usr/local/mysql/var/mysql.sock --port=3306root 30726 11268 0 12:58 pts/2 00:00:00 grep mysql
可知，当前mysql.sock文件路径是/usr/local/mysql/var/mysql.sock，
解决办法：做软链接
[root@test-huanqiu ~]# ll /usr/local/mysql/var/mysql.sock rwxrwxrwx. 1 mysql mysql 0 Nov 29 12:55 /usr/local/mysql/var/mysql.sock [root@test-huanqiu ~]# rm -f /var/lib/mysql/mysql.sock [root@test-huanqiu ~]# ln -s /usr/local/mysql/var/mysql.sock /var/lib/mysql/mysql.sock
这样就没问题了
[root@test-huanqiu ~]# mysql -p123456 mysql>
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启动mysql的时候报错：
Starting MySQL.... ERROR! The server quit without updating PID file (/data/mysql/data/mysql.pid).
尝试的解决办法：
（1）权限问题
可能是mysql.pid文件没有写的权限，将mysql的安装目录和数据目录的权限都设置成mysql启动用户权限。比如都修改为mysql:mysql权限
（2）可能进程里已经存在mysql进程
ps -ef|grep mysql 查出要是有mysql进程存在，就kill掉，再尝试重启mysql
（3）可能是多次在机器上安装mysql，有残余数据影响了服务的启动。
去mysql的数据目录看看，如果存在mysql-bin.index，就立刻删掉它，它就是罪魁祸首了！
（4）mysql在启动时没有指定配置文件时会使用/etc/my.cnf配置文件，请打开这个文件查看在[mysqld]节下有没有指定数据目录。
在[mysqld]下添加设置，如datadir = /data/mysql/data
（5）skip-federated字段问题
检查一下my.cnf文件中有没有没被