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DBIx::Class::CDBICompat.3pm

NAME

DBIx::Class::CDBICompat - Class::DBI Compatibility layer.

SYNOPSIS

   package My::CDBI;
   use base qw/DBIx::Class::CDBICompat/;
 
   ...continue as Class::DBI...
 
 

DESCRIPTION

DBIx::Class features a fully featured compatibility layer with Class::DBI and some common plugins to ease transition for existing CDBI users.

This is not a wrapper or subclass of DBIx::Class but rather a series of plugins. The result being that even though you're using the Class::DBI emulation layer you are still getting DBIx::Class objects. You can use all DBIx::Class features and methods via CDBICompat. This allows you to take advantage of DBIx::Class features without having to rewrite your CDBI code.

Plugins

CDBICompat is good enough that many CDBI plugins will work with CDBICompat, but many of the plugin features are better done with DBIx::Class methods.

Class::DBI::AbstractSearch

"search_where()" is fully emulated using DBIC's search. Aside from emulation there's no reason to use "search_where()".

Class::DBI::Plugin::NoCache

"nocache" is fully emulated.

Class::DBI::Sweet

The features of CDBI::Sweet are better done using DBIC methods which are almost exactly the same. It even uses Data::Page.

Class::DBI::Plugin::DeepAbstractSearch

This plugin will work, but it is more efficiently done using DBIC's native search facilities. The major difference is that DBIC will not infer the join for you, you have to tell it the join tables.

Choosing Features

In fact, this class is just a recipe containing all the features emulated. If you like, you can choose which features to emulate by building your own class and loading it like this:

   package My::DB;
   __PACKAGE__->load_own_components(qw/CDBICompat/);
 
 

this will automatically load the features included in My::DB::CDBICompat, provided it looks something like this:

   package My::DB::CDBICompat;
   __PACKAGE__->load_components(qw/
     CDBICompat::ColumnGroups
     CDBICompat::Retrieve
     CDBICompat::HasA
     CDBICompat::HasMany
     CDBICompat::MightHave
   /);
 
 

LIMITATIONS

Unimplemented

The following methods and classes are not emulated, maybe in the future.

Class::DBI::Query

Deprecated in Class::DBI.

Class::DBI::Column

Not documented in Class::DBI. CDBICompat's columns() returns a plain string, not an object.

data_type()

Undocumented CDBI method.

Limited Support

The following elements of Class::DBI have limited support.

Class::DBI::Relationship

The semi-documented Class::DBI::Relationship objects returned by "meta_info($type, $col)" are mostly emulated except for their "args" method.

Relationships

Relationships between tables (has_a, has_many...) must be declared after all tables in the relationship have been declared. Thus the usual CDBI idiom of declaring columns and relationships for each class together will not work. They must instead be done like so:

     package Foo;
     use base qw(Class::DBI);
 
     Foo->table("foo");
     Foo->columns( All => qw(this that bar) );
 
     package Bar;
     use base qw(Class::DBI);
 
     Bar->table("bar");
     Bar->columns( All => qw(up down) );
 
     # Now that Foo and Bar are declared it is safe to declare a
     # relationship between them
     Foo->has_a( bar => "Bar" );
 
 

AUTHORS

Matt S. Trout <mst@shadowcatsystems.co.uk>

LICENSE

You may distribute this code under the same terms as Perl itself.