Class::DBI::BaseDSN - DSN sensitive base class


Class::DBI::BaseDSN - DSN sensitive base class


  package My::DBI;
  use base 'Class::DBI::BaseDSN'; # we'll decide later what our real
                                   # parent class will be
  __PACKAGE__->set_db( Main => $ENV{TESTING} ? @test_dsn : @real_dsn );


Class::DBI::BaseDSN acts as a placeholder for a base class which will be switched for a specific Class::DBI extension when you specify the dsn of the database to connect to.

For example in this case, the Class::DBI::BaseDSN will replace itself with Class::DBI::mysql when the set_db call is executed.

 package Example::DBI;
 use base 'Class::DBI::BaseDSN';
 __PACKAGE__->set_db( Main => 'dbi:mysql:example', 'user', 'pass' );

Since this happens at runtime you could pass the dsn as a variable and so have it use a completely different extension automatically. This is especially useful for testing, or for applications where dsn may be a configuration option.

If there is no matching extension found, Class::DBI::BaseDSN replaces itself with Class::DBI.


Richard Clamp <>


Thanks go to Michael Schwern for a snippet to fake out caller, and for hashing out some of the finer points of the approach on the cdbi-talk list.


the Class::DBI manpage

 Class::DBI::BaseDSN - DSN sensitive base class