<tr>
<td>[% book.title %]</td>
<td>[% book.rating %]</td>
+ <td></td>
</tr>
[% END -%]
</table>
associated with tables in a relational database. Matt Trout's
L<DBIx::Class|DBIx::Class> (abbreviated as "DBIC") has rapidly emerged
as the Perl-based ORM technology of choice. Most new Catalyst
-applications rely on DBIC, as will this tutorial.
+applications rely on DBIx::Class, as will this tutorial.
-Although DBIC has included support for a C<create=dynamic> mode to
-automatically read the database structure every time the application
-starts, it's use is no longer recommended. While it can make
-for "flashy" demos, the use of the C<create=static> mode we use below
-can be implemented just as quickly and provides many advantages (such
-as the ability to add your own methods to the overall DBIC framework,
-a technique that we see in Chapter 4).
+Although DBIx::Class has included support for a C<create=dynamic> mode
+to automatically read the database structure every time the
+application starts, it's use is no longer recommended. While it can
+make for "flashy" demos, the use of the C<create=static> mode we use
+below can be implemented just as quickly and provides many advantages
+(such as the ability to add your own methods to the overall DBIC
+framework, a technique that we see in Chapter 4).
-=head2 Make Sure You Have a Recent Version of the DBIC Model
+=head2 Make Sure You Have a Recent Version of the DBIx::Class Model
First, let's be sure we have a recent version of the DBIC helper,
L<Catalyst::Model::DBIC::Schema|Catalyst::Model::DBIC::Schema>, by
0.23 or higher.
-=head2 Create Static DBIC Schema Files
+=head2 Create Static DBIx::Class Schema Files
Use the model helper with the C<create=static> option to read the
database with
has a subdirectory called "Result". This "Result" subdirectory then
has files named according to each of the tables in our simple database
(C<Authors.pm>, C<BookAuthors.pm>, and C<Books.pm>). These three
-files are called "Result Classes" in DBIC nomenclature. Although the
+files are called "Result Classes" in DBIx::Class nomenclature. Although the
Result Class files are named after tables in our database, the classes
correspond to the I<row-level data> that is returned by DBIC (more on
this later, especially in
B<NOTE:> Older versions of
L<Catalyst::Model::DBIC::Schema|Catalyst::Model::DBIC::Schema> use the
-deprecated DBIC C<load_classes> technique instead of the newer
+deprecated DBIx::Class C<load_classes> technique instead of the newer
C<load_namspaces>. For new applications, please try to use
C<load_namespaces> since it more easily supports a very useful DBIC
technique called "ResultSet Classes." If you need to convert an
The rating for each book should appear on each row, but the "Author(s)"
column will still be blank (we will fill that in later).
-Also notice in the output of the C<script/myapp_server.pl> that DBIC
-used the following SQL to retrieve the data:
+Also notice in the output of the C<script/myapp_server.pl> that
+DBIx::Class used the following SQL to retrieve the data:
SELECT me.id, me.title, me.rating FROM books me
template -- the wrapper will provide the overall feel of the page.
-=head2 Updating the Generated DBIC Result Class Files
+=head2 Updating the Generated DBIx::Class Result Class Files
Let's manually add some relationship information to the auto-generated
Result Class files. (Note: if you are using a database other than
C<Important Note:> Although this tutorial uses plural names for both
the names of the SQL tables and therefore the Result Classes (after
all, C<Schema::Loader> automatically named the Result Classes from the
-names of the SQL tables it found), DBIC users prefer singular names
-for these items. B<Please try to use singular table and DBIC
+names of the SQL tables it found), DBIx::Class users prefer singular
+names for these items. B<Please try to use singular table and DBIC
model/Result Class names in your applications.> This tutorial will
migrate to singular names as soon as possible (patches welcomed).
B<Note that while singular is preferred for the DBIC model, plural is
perfectly acceptable for the names of the controller classes.> After
all, the C<Books.pm> controller operates on multiple books.
-This code defines both a C<has_many> and a C<many_to_many> relationship.
-The C<many_to_many> relationship is optional, but it makes it easier to
-map a book to its collection of authors. Without it, we would have to
-"walk" though the C<book_authors> table as in
-C<$book-E<gt>book_authors-E<gt>first-E<gt>author-E<gt>last_name>
-(we will see examples on how to use DBIC objects in your code soon,
+This code defines both a C<has_many> and a C<many_to_many>
+relationship. The C<many_to_many> relationship is optional, but it
+makes it easier to map a book to its collection of authors. Without
+it, we would have to "walk" though the C<book_authors> table as in
+C<$book-E<gt>book_authors-E<gt>first-E<gt>author-E<gt>last_name> (we
+will see examples on how to use DBIx::Class objects in your code soon,
but note that because C<$book-E<gt>book_authors> can return multiple
authors, we have to use C<first> to display a single author).
-C<many_to_many> allows us to use the shorter
-C<$book-E<gt>authors-E<gt>first-E<gt>last_name>.
-Note that you cannot define a C<many_to_many> relationship without
-also having the C<has_many> relationship in place.
+C<many_to_many> allows us to use the shorter C<$book-E<gt>authors-
+E<gt>first-E<gt>last_name>. Note that you cannot define a
+C<many_to_many> relationship without also having the C<has_many>
+relationship in place.
Then edit C<lib/MyApp/Schema/Result/Authors.pm> and add relationship
information as follows (again, be careful to put in above the C<1;> but
Let's add a new column to our book list page that takes advantage of
the relationship information we manually added to our schema files in
-the previous section. Edit C<root/src/books/list.tt2> and add the
-following code below the existing table cell that contains
-C<book.rating> (IOW, add a new table cell below the existing two
-C<E<lt>tdE<gt>> tags but above the closing C<E<lt>/trE<gt>> and
-C<E<lt>/tableE<gt>> tags):
+the previous section. Edit C<root/src/books/list.tt2> and replace
+the "empty" tabase cell with the following:
...
<td>
If you are still running the development server with C<DBIC_TRACE>
enabled, you should also now see five more C<SELECT> statements in the
debug output (one for each book as the authors are being retrieved by
-DBIC):
+DBIx::Class):
SELECT me.id, me.title, me.rating FROM books me:
SELECT author.id, author.first_name, author.last_name FROM book_authors me
projects / catagits/Catalyst-Manual.git / blobdiff