For most databases, you can also do:

 my $dbh = DBI->connect( 'DBI:mysql:mysql', 'username', 'password' )
           || die $DBI::errstr;
 $dbh->do( 'use ' . DBNAME );
[download]

Another option is putting the entire DBI DSN in the constant:

 use constant DSN => 'DBI:mysql:database=devel';
 ...
 my $dbh = DBI->connect( DSN, 'username', 'password' )
           || die $DBI::errstr;
[download]

Chris

M-x auto-bs-mode