connect

connect is used to create a connection to a data source. Here is an example of a simple connect statement:

$db_handle = DBI->connect($datasource, $user, $password)      or die ("Error: $DBI::errstr\n");

A hash of attributes can also be passed:

$db_handle = DBI->connect($datasource, $user, $password, \%attr)      or die ("Error: $DBI::errstr\n"); 

If there is an error connecting, $DBI::errstr will be set, and the call will die with the message we include in the die call.

The $datasource string can be quite complex. For MySQL, it is commonly something like this:

DBI:mysql:PerlBook

where mysql is the DBD and PerlBook is the database name. If the data source happens to be on another server, then the data source needs to contain a bit more information.

DBI:mysql:[e-mail]:989

In this case, we specify the URL of the server where the database hosts. Also, we specify the port (989) that the database server listens on.