第一个问题：
root@b-ThinkPad-X230s:/usr/local/mysql/bin# ./mysqld_safe start （开启mysql的服务！）151123 14:19:04 mysqld_safe Logging to '/usr/local/mysql/data/b-ThinkPad-X230s.err'.151123 14:19:04 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data151123 14:19:05 mysqld_safe mysqld from pid file /usr/local/mysql/data/b-ThinkPad-X230s.pid ended
root@b-ThinkPad-X230s:/usr/local/mysql/bin# ./mysql --user=mysql （使用mysql用户登录）ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2) （报错！）
以为是用户的问题，然后尝试换一个用户名：
root@b-ThinkPad-X230s:/usr/local/mysql/bin# ./mysql -u root （使用root用户登录）ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2) （报错！）
然后想着是否是没有用户设置密码的问题，因为貌似是不用密码也可以登录的，先尝试设置密码：
root@b-ThinkPad-X230s:/usr/local/mysql/bin# ./mysqladmin -u mysql password "123456"./mysqladmin: connect to server at 'localhost' failederror: 'Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)'Check that mysqld is running and that the socket: '/tmp/mysql.sock' exists!
查看服务是否已经启动：
root@b-ThinkPad-X230s:/tmp# ps -aux | grep "mysql"root 4518 0.0 0.0 13708 2296 pts/11 S+ 14:35 0:00 grep --color=auto mysql (没有启动mysql服务)
已经尝试遍了网上搜寻的所有解决办法，最后按照同事的提示，重新编译安装吧，然后重新编译安装！
然后就通过了，可以正常登录！比较无语！
转载于:https://www.cnblogs.com/persistcat/p/4988436.html
