Returns a positive FrontBase link identifier on success,
or an error message on failure.
fbsql_connect() establishes a
connection to a FrontBase server. The following defaults are
assumed for missing optional parameters: hostname = 'NULL',
username = '_SYSTEM' and
password = empty password.
If a second call is made to
fbsql_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 fbsql_close().
See also fbsql_pconnect() and
fbsql_close().