> > create table foo ( id serial not null, foo text );
> > create table bar ( foo_id int not null references foo(id), bar text);
>
> Neither has a primary key, and RDBO requires every table to have one. But
> I'll assume you meant this:
>
> create table foos
> (
> id serial not null primary key,
> foo text
> );
>
> create table bars
> (
> foo_id int not null primary key references foos (id),
> bar text
> );
Apologies. You are correct. I did mean to have primary key on those.
> Given those tables, this is what the Loader makes of them:
>
> package Bar;
> ...
> __PACKAGE__->meta->setup
> (
> table => 'bars',
> columns =>
> [
> foo_id => { type => 'integer', not_null => 1 },
> bar => { type => 'text' },
> ],
>
> primary_key_columns => [ 'foo_id ' ],
>
> foreign_keys =>
> [
> foo =>
> {
> class => 'Foo',
> key_columns => { foo_id => 'id' },
> },
> ],
> );
>
> package Foo;
> ...
> __PACKAGE__->meta->setup
> (
> table => 'foos',
> columns =>
> [
> id => { type => 'serial', not_null => 1 },
> foo => { type => 'text' },
> ],
>
> primary_key_columns => [ 'id' ],
>
> relationships =>
> [
> bars =>
> {
> class => 'Bar',
> key_columns => { id => 'foo_id' },
> type => 'one to many',
> },
> ],
> );
>
> Notice that it's made the foo->bar relationship a one-to-many. It's not
> quite smart enough to see that both foo.id and bar.foo_id are unique keys
> (primary keys, in fact), making it a one-to-one relationship.
>
> I've updated the Loader in SVN to correctly detect one-to-one relationships,
> so now it produces a Foo class like this:
>
> package Foo;
> ...
> __PACKAGE__->meta->setup
> (
> table => 'foos',
> columns =>
> [
> id => { type => 'serial', not_null => 1 },
> foo => { type => 'text' },
> ],
>
> primary_key_columns => [ 'id' ],
>
> relationships =>
> [
> bar =>
> {
> class => 'Bar',
> column_map => { id => 'foo_id' },
> type => 'one to one',
> },
> ],
> );
>
> (Note that I changed "key_columns" to "column_map" too.)
I was using add_relationships() to manually set my type to "one to
one" anyway. I was also using column_map.
> Now for the code:
>
> my $bar = Bar->new;
> my $foo = Foo->new;
> $foo->bar($bar);
> $foo->bar->bar('some text');
> $foo->save;
>
> This now runs successfully, executing the following SQL:
>
> # Save the foo row
> INSERT INTO foos (foo, id) VALUES (NULL, 1);
>
> # Check to see if $bar already exists in the database.
> # (In this case, it doesn't.)
> SELECT bar, foo_id FROM bars WHERE foo_id = 1
>
> # Add the bar row
> INSERT INTO bars (bar, foo_id) VALUES ('some text', 1);
>
> Notice that the "cascade" flag is not used at all. If it were added:
>
> $foo->save(cascade => 1);
>
> it would not alter the SQL at all, nor would it add any more queries. It
> would, however, check to see if $bar has unsaved changes. It doesn't (it
> was just saved) so $bar does not need to be (re)save()d.
Yep, works for me now too. Thanks a bunch!
I also tested your fix for not running the UPDATE sql where there were
no fields to update, and it is also work a treat. Thanks again.
--
"Cats are smarter than dogs. You can't get eight cats to pull a sled
through snow." - Jeff Valdez
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