DataMapper ORM v1.8.0

[eluser]WanWizard[/eluser]
[quote author="Arministrator" date="1306423505"]I need to be able to access just donations, without donors. And a donation can be of bloodype A, B, etc, so I guess it has many bloodtypes.[/quote]
Still, from a database design perspective, a donation doesn't have a bloodtype.

If you need to know all donations for blood type B+, you need to query all donations done by donors with that bloodtype. Now you have to do double administration, which the chance of errors if you're not careful (you can easily relate a donor with O with a donation with B+).

If you want to list donations, run the query from the donations object:

Code:

$donations = new Donation();
$donations->include_related('bloodtype')->where_related_donator('email', $this->input->post('email'))->get_iterated();

You can limit the fields in the result with a select() or by listing fields to include on the include_related(), if needed.

If you dump the objects, you might see redundant data not related to the database record. No worries, those are references, they don't take up any space (except for the reference of course).