Question

models:

class Detail(models.Model):
    def __unicode__(self):
            return self.title
    title = models.CharField(max_length=32)

class Cars(models.Model):
    def __unicode__(self):
            return self.name
    name = models.CharField(max_length=32, unique=True)
    details = models.ManyToManyField(Detail)

So, every car has a many details – wheels, engine, etc. How to do this: in Django Admin situated Cars menu, in that menu we have a many lines of details (like in tutorial).
In admin I use:

class DetailInline(admin.TabularInline):
    model = Detail
    extra = 6
class CarsAdmin(admin.ModelAdmin):
    inlines = [DetailInline]

But it has error: Detail has no ForeignKey to Cars. How to fix it?

Answer 1

Django does not natively let you add a reverse inline.
i.e. You can have the Detail page contain an inline admin of all the Cars that contain a ForeignKey to that particular Detail. However, the reverse is not natively possible.

There is a workaround though wherein you have to override the admin template a bit. There is a previous SO question about this here: Inline-like solution for Django Admin where Admin contains ForeignKey to other model