Describes the type of connection in use for the connection, including the server host name.
The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect is assumed. If no such link is found, it will try to create one as if mysql_connect had been called with no arguments. If no connection is found or established, an E_WARNING level error is generated.
Returns a string describing the type of MySQL connection in use for the connection or false on failure.