ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/home/omm/proj/mysql/mysql.sock' (2)

The error message you received indicates that the MySQL client is unable to connect to the local MySQL server through the specified socket file '/home/omm/proj/mysql/mysql.sock'. This can occur due to several reasons. Here are a few possible solutions:

1. Verify MySQL server status: Ensure that the MySQL server is running and accessible on the local machine. You can check the status using the following command:

   sudo service mysql status

If the server is not running, start it using:

   sudo service mysql start

2. Check the correct socket file path: Confirm that the socket file path specified in your MySQL client configuration is correct. It should match the actual location of the socket file on your system. By default, the socket file is usually located at '/var/run/mysqld/mysqld.sock'.

3. Specify the socket file explicitly: If the socket file is located in a different directory or has a different name, you can specify it explicitly when connecting to the MySQL server. Use the '--socket' option followed by the correct socket file path. For example:

   mysql --socket=/var/run/mysqld/mysqld.sock -u your_username -p

4. Check MySQL server configuration: Ensure that the MySQL server's configuration file (typically 'my.cnf') has the correct socket file location specified. Look for the 'socket' directive under the '[mysqld]' section and make sure it points to the correct path.

5. Verify socket file permissions: Check if the user running the MySQL client has sufficient permissions to access the socket file. The user should have read and write permissions for the socket file and its parent directories.

If none of these solutions resolve the issue, there may be a problem with your MySQL installation or configuration. It's recommended to consult with a system administrator or refer to the MySQL documentation for further troubleshooting steps.