in reply to Re: Catalyst: model & context object usage
in thread Catalyst: model & context object usage

Thanks Actualize. Here is the list sub. 

sub list : Local {
    # Retrieve the usual Perll OO '$self' for this object. $c is the C
+atalyst
    # 'Context' that's used to 'glue together' the various components
    # that make up the application.
    my ($self, $c) = @_;

    # Retrieve all of the book records as book model objects and store
+ in the
    # stash where they can be accessed by the TT template
    $c->stash->{books} = [$c->model('DB::Books')->all];

    # Set the TT template to use. You will almost always want to do th
+is
    # in your action methods (action methods respond to user input in
    # your controllers).
    $c->stash->{template} = 'books/list.tt2';
}

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Re^3: Catalyst: model & context object usage
by actualize (Monk) on Aug 11, 2008 at 06:49 UTC

    Your sub list is exactly the same as it is in the tutorial. After looking over the tutorial and thinking about the error, it looks like the id field for the author is not being passed to the object. There are a few reasons this could happen.

  • It could be because you are typing in the wrong url
    • Here's the right one: http://localhost:3000/books/url_create/TCPIP_Illustrated_Vol-2/5/4
  • It also could be because there is an error in the code I posted above for joining with the author id:
    • # Add a record to the join table for this book, mapping to 
# appropriate author
$book->add_to_book_authors({author_id => $author_id});
# Note: Above is a shortcut for this:
# $book->create_related('book_authors', {author_id => $author_id});
# Assign the Book object to the stash for display in the view
$c->stash->{book} = $book;

    [download]
  • It could be some errors in the DBIx::Class setup from "More Catalyst Basics".
    • If you happen to leave out a line or write an error in your schema files, your queries may not come out correctly.

    -Actualize
[reply]
[d/l]
      Here is the error while accessing url http://localhost:3000/books/url_create/TCPIP_Illustrated_Vol-2/5/4. 
      DBI Exception: DBD::Oracle::st execute failed: ORA-01400: cannot inser
+t NULL into ("SDB2"."BOOKS"."ID") (DBD ERROR: OCIStmtExecute) [for St
+atement "INSERT INTO books (rating, title) VALUES (?, ?)" with ParamV
+alues: :p1='5', :p2='TCPIP_Illustrated_Vol-2']

      [download]
      There is a way to bypass the error, assigning a value to id(Primary Key). Primary key is supposed to be self-increase, right ? 
      sub url_create : Local {
       my ($self, $c, $title, $rating, $author_id) = @_;

# Call create() on the book model object. Pass the table 
        # columns/field values we want to set as hash values
        my $book = $c->model('DB::Books')->create({

      [download]

      id => '10', 

                      title  => $title,
                rating => $rating
            });

}

      [download]
[reply]
[d/l]
[select]

        I don't know Oracle but in theory if you set up your database so that book.id is a primary key and that it auto increments then you should be able to pass a NULL value as the id so that it automatically takes the next value.

        Are you in a different tutorial that uses Oracle? Otherwise I would recommend using sqlite and doing everything to the letter. That way you only have to worry about getting the web app running and not if the instructions for the sqlite database are compatible with your database.

        Also you might want to post your schema files.

        -Actualize
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