Django Model Filter

Question

I've spent the last few hours looking at Django Docs and similar questions on here but I'm still unclear on how to tackle the problem...

In essense I want to access the list of email addresses relevent to a certain group, so I can send an email to these customers who are part of this group (named group_one, group_two etc)

class Group(models.Model):
  name = models.CharField(primary_key=True)
  mailing_list = models.ManyToManyField("Customer", null=True)  

class Customer(models.Model):
  name = models.CharField()
  email = models.EmailField(primary_key=True)

I've tried

group_mail_list = Group.objects.filter(name=group_two)

And this returns an Query Object for group_two but when I try to do a __contains filter I get a error:

TypeError: Related Field has invalid lookup: contains

Anyone help me out? Not sure if it's because it's a many-to-many relationship perhaps?

Thanks in advance :)

Answer 1

What you really want is Customers, then. It seems counter-intuitive on the surface, because you're wanting emails for a Group, but that field is on Customer not Group:

Customer.objects.filter(group__name='group_two').values_list('email')