如果您的Linux机器上安装了XAMPP，请尝试将my.cnf文件从/opt/lampp/etc/my.cnf复制到/etc/my.cnf

然后，再次运行mysql -u root…现在您应该有了正确的套接字，并且能够运行MySQL客户端。

试试这个:

mysql -h 127.0.0.1 -P 3306 -u root -p <database>

另外(看看它是否在运行):

telnet 127.0.0.1 3306 

可能只是my.cnf文件中的错误配置，在/etc/某处(取决于Linux发行版)。

尝试重新启动服务器

sudo /usr/local/mysql/support-files/mysql.server start

如果出现任何错误，请按照以下步骤进行操作

mysqld

您将看到下面的日志。注意MySQL目录中突出显示的部分

mysqld: Can't change dir to '/usr/local/mysql-5.7.14-osx10.11-x86_64/data/' (Errcode: 13 - Permission denied) 2016-10-04T14:09:19.392581Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details). 2016-10-04T14:09:19.392847Z 0 [Warning] Insecure configuration for --secure-file-priv: Current value does not restrict location of generated files. Consider setting it to a valid, non-empty path. 2016-10-04T14:09:19.392921Z 0 [Note] mysqld (mysqld 5.7.14) starting as process 1402 ... 2016-10-04T14:09:19.397569Z 0 [Warning] Can't create test file /usr/local/mysql-5.7.14-osx10.11-x86_64/data/Sudharshan.lower-test 2016-10-04T14:09:19.397597Z 0 [Warning] Can't create test file /usr/local/mysql-5.7.14-osx10.11-x86_64/data/Sudharshan.lower-test 2016-10-04T14:09:19.397712Z 0 [ERROR] failed to set datadir to /usr/local/mysql-5.7.14-osx10.11-x86_64/data/ 2016-10-04T14:09:19.397776Z 0 [ERROR] Aborting 2016-10-04T14:09:19.397795Z 0 [Note] Binlog end 2016-10-04T14:09:19.397925Z 0 [Note] mysqld: Shutdown complete

sudo chown -R _mysql:_mysql /usr/local/mysql-5.7.14-osx10.11-x86_64

注意前面日志中的MySQL文件夹路径/usr/local，在我的例子中，它是MySQL -5.7.14-osx10.11-x86_64，您必须根据您在计算机上获得的日志更新它，以提供对MySQL目录的读访问

sudo /usr/local/mysql/support-files / mysql。服务器启动

启动MySQL 成功!

在我的情况下，我错过了mysql服务器。所以在通过sudo apt-get install mysql-server安装它之后，我又可以连接了。

升级MySQL为我解决了这个问题。在基于rhel的服务器上，只需运行:

sudo yum upgrade mysql-server

似乎你的MYSQL停止了。使用下面的命令重新启动MySQL

sudo service mysql start