I think you could construct a Q object like this:
from django.db.models import Q
query = Q()
for preference in user.preferences.all():
query |= Q(dish=preference.dish) & Q(ingredient=preference.ingredient)
Meal.objects.filter(query)
That returns the meals where their (ingredient, dish) combination match at
least one of the preferences of the user.
On Wed, Nov 26, 2014 at 3:54 PM, <lnzy3...@gmx.de> wrote:
> Hi,
> let’s assume I have the following model:
>
> *class Ingredient(models.Model):*
> * ingredient= models.CharField(max_length=255)*
> *class Dish(models.Model):*
> * BREAKFAST = 'bf'*
> * LUNCH = 'l'*
> * DINNER = 'D'*
> * DISH_CHOICES = (*
> * (BREAKFAST, 'Breakfast'),*
> * (LUNCH, 'Lunch'),*
> * (DINNER, 'Dinner'),*
> * )*
> * dish =
> models.CharField(max_length=32,choices=DISH_CHOICES,unique=True)*
>
> *class Preference(models.Model):*
> * ingredient= models.ForeignKey(Ingredient)*
> * dish = models.ForeignKey(Dish)*
> * date_created = models.DateTimeField(auto_now_add=True)*
> * date_updated = models.DateTimeField(auto_now=True, verbose_name='Date
> updated')*
> * owner = models.ForeignKey(User, related_name='preferences')*
>
> *class Meal(models.Model):*
> * name = models.CharField(max_length=255)*
> * ingredient= models.ManyToManyField(Ingredient)*
> * kalorins = models.IntegerField()*
> * thumbnail = models.URLField(blank=True)*
> * dish= models.ForeignKey(Dish)*
>
> I want to execute a database query in the view resulting all meals that
> would match the preference’s of a user.
> But something like: *result =
> Meal.objects.filter(ingredient__in=user.request.name.pfreferences) *will
> select all the meals witch are in the preference list of the user,
> regardless his choice of the “Dish Type”. So if a person only likes tomatos
> for breakfast, he also will get all meals with tomates for lunch and dinner.
>
> So I am looking for a way, which returns only the “*Meal*s” where the
> *ingredient*s and the *dish *BOTH match the *ingredient*s and the *dish *of
> the *user’s Preference.*
> I haven’t found anything in the django books I have or the documentation
> Thanks a lot.
> Best Regards,
> Mike
>
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "Django users" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to django-users+unsubscr...@googlegroups.com.
> To post to this group, send email to django-users@googlegroups.com.
> Visit this group at http://groups.google.com/group/django-users.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/django-users/trinity-f0d51c02-a559-4c2a-b1d1-e807598864ff-1417028087688%403capp-gmx-bs08
> <https://groups.google.com/d/msgid/django-users/trinity-f0d51c02-a559-4c2a-b1d1-e807598864ff-1417028087688%403capp-gmx-bs08?utm_medium=email&utm_source=footer>
> .
> For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups
"Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to django-users+unsubscr...@googlegroups.com.
To post to this group, send email to django-users@googlegroups.com.
Visit this group at http://groups.google.com/group/django-users.
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-users/CALn3ei0t_uWYDK7wk9ems1M9ZV8vRuXbTVT9MSTynuxUGhYWiQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.
