6.3 Connecting to the MySQL server

MySQL client programs generally require that you specify connection parameters when you want to access a MySQL server: the host you want to connect to, your user name and your password. For example, the mysql client can be started like this (optional arguments are enclosed between `[' and `]'):

shell> mysql [-h host_name] [-u user_name] [-pyour_pass]

Alternate forms of the -h, -u and -p options are --host=host_name, --user=user_name and --password=your_pass. Note that there is no space between -p or --password= and the password following it.

Note: Specifing a password on the command line is not secure! Any user on your system may then find out your password by typing a command like: ps auxww. 4.15.4 Option files.

mysql uses default values for connection parameters that are missing from the command line:

  • The default hostname is localhost.
  • The default user name is your Unix login name.
  • No password is supplied if -p is missing.

Thus, for a Unix user joe, the following commands are equivalent:

shell> mysql -h localhost -u joe
shell> mysql -h localhost
shell> mysql -u joe
shell> mysql

Other MySQL clients behave similarly.

On Unix systems, you can specify different default values to be used when you make a connection, so that you need not enter them on the command line each time you invoke a client program. This can be done in a couple of ways:

  • You can specify connection parameters in the [client] section of the `.my.cnf' configuration file in your home directory. The relevant section of the file might look like this:
    4.15.4 Option files.
  • You can specify connection parameters using environment values. The host can be specified using MYSQL_HOST. The MySQL user name can be specified using USER (this is for Windows only). The password can be specified using MYSQL_PWD (but this is insecure; see next section).

If connection parameters are specified in multiple ways, values specified on the command line take precedence over values specified in configuration files and environment variables, and values in configuration files take precedence over values in environment variables.