CODEWITHSUNDEEP
djangorelationship
TMD
TMD

Reputation: 191

Django ForeignKey

I'm struggling to do a reverse search via the shell for a foreign key

models.py: 

class Investor(models.Model):
 first_name = models.CharField(max_length = 100)
 last_name = models.CharField(max_length = 100)

 def __str__ (self):
    return '%s %s' % (self.first_name, self.last_name)

class Investment(models.Model):
 investor = models.ForeignKey(Investor, on_delete=models.CASCADE)
 feeder = models.ForeignKey(Fund, on_delete=models.CASCADE)   
 amount = models.DecimalField(max_digits=20, decimal_places=2, default="1")

 def __str__ (self):
    return self.investor

class Fund(models.Model):
 feeder = models.CharField(max_length=100)

 def __str__ (self):
    return  self.feeder

If I enter the shell:

a = Investment.objects.get(pk=1)
a.investor.first_name -> this works

On the other hand :

b = Investor.objects.get(pk=1)
b.investment doesn't work... 
b.investor doesn't work
b.investment.feeder neither..

Always got the error 'Investor has not attributed '....' -> How can i search through the reverse relationships? Thanks !!

Upvotes: 1

Views: 43

Answers (1)

Daniel Roseman
Daniel Roseman

Reputation: 599480

A foreign key is a one-to-many relationship, not one-to-one. Here an Investment has one Investor, but an Investor has many Investments. So from your Investor you need to use the reverse relation, which be default ends in set, and is a Manager:

b.investment_set.all()

Upvotes: 2

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