MySQL (PDO)
PHP Manual

PDO_MYSQL DSN

Connecting to MySQL databases

Description

The PDO_MYSQL Data Source Name (DSN) is composed of the following elements:

DSN prefix

The DSN prefix is mysql:.

host

The hostname on which the database server resides.

port

The port number where the database server is listening.

dbname

The name of the database.

unix_socket

The MySQL Unix socket (shouldn't be used with host or port).

charset

The character set. See the character set concepts documentation for more information.

Examples

Example #1 PDO_MYSQL DSN examples

The following example shows a PDO_MYSQL DSN for connecting to MySQL databases: 

mysql:host=localhost;dbname=testdb
More complete examples: 
mysql:host=localhost;port=3307;dbname=testdb
mysql:unix_socket=/tmp/mysql.sock;dbname=testdb

Notes

Note: Unix only:

When the host name is set to "localhost", then the connection to the server is made through a domain socket. If PDO_MYSQL is compiled against libmysqlclient then the location of the socket file is at libmysqlclient's compiled in location. If PDO_MYSQL is compiled against mysqlnd a default socket can be set through the pdo_mysql.default_socket setting.