今天安装mysql，连接MySQL时报错mysql: [Warning] Using a password on the command line interface can be insecure. ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

通过ls命令查看，发现/var/run/mysqld目录并不存在,创建这个文件夹sudo mkdir /var/run/mysqld,然后修改文件夹的所属者sudo chown mysql:mysql /var/run/mysqld.

重启MySQL服务sudo /etc/init.d/mysql restart

再次尝试连接MySQL mysql -uroot -p, 成功。