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.