Connect to MySQL from the command line over SSH (error 2002)

In an SSH session on your hosting, the mysql client lets you query your databases from the command line, and mysqldump lets you make a copy of them. This article explains how to connect, and what to do if the client returns error 2002 "Can't connect to local MySQL server through socket".

Prerequisites

Active SSH access to your hosting (see Connect to your hosting via SSH).
A MySQL database and a user with access to it, with its password.

Before you start

The connection settings are the ones the Apanel console shows in Databases → MySQL, in the Database configuration block: Hostname localhost and Port 3306.
With localhost (or without the -h option), the client goes through the server's local socket file. With -h 127.0.0.1, it goes through the local network (TCP) on port 3306. Both reach the same database server.
The mysql and mysqldump commands are installed in your SSH environment.

Connect

Connect to your hosting via SSH.
Start the client, giving the user and the database:
```
mysql -u username -p database_name
```
Enter the user's password when prompted. The -p option without a value makes the client ask for the password, so it appears neither on screen nor in your command history.
Type exit to leave the client.

To export a database to a file, mysqldump takes the same options:

mysqldump -u username -p database_name > backup.sql

Troubleshooting

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '…': the client is looking for the socket at a path that does not exist on our servers (for example /var/run/mysqld/mysql.sock). That path usually comes from a socket= setting in a ~/.my.cnf file, a -S or --socket option in the command, or a script copied from another server. Remove that setting, or force a TCP connection:
```
mysql -h 127.0.0.1 -P 3306 -u username -p database_name
```
ERROR 1045 (28000): … Access denied for user: the username or password is wrong, or the user has no access to this database. Check them in the Apanel console, on the database's users tab (see Create a MySQL database and its user).
You prefer a graphical interface: phpMyAdmin, available from the Apanel console, does the same without SSH.