int mysql_connect ([string
[:/path/to/socket] [, string
username [, string
Returns a positive MySQL link identifier on success, or an error message on failure.
mysql_connect() establishes a connection to a MySQL server. The following defaults are assumed for missing optional parameters: host:port = 'localhost:3306', username = name of the user that owns the server process and password = empty password.
The hostname string can also include a port number. eg. "hostname:port" or a path to a socket eg. ":/path/to/socket" for the localhost.
Note: Support for ":port" was added in PHP 3.0B4.
Support for ":/path/to/socket" was added in PHP 3.0.10.
You can suppress the error message on failure by prepending '@' to the function name.
If a second call is made to mysql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned.
The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mysql_close().