Hulk Hulk - 2 months ago 12
Python Question

Django Foreign key queries

In the following model:

class header(models.Model):
title = models.CharField(max_length = 255)
created_by = models.CharField(max_length = 255)

def __unicode__(self):
return self.id()

class criteria(models.Model):
details = models.CharField(max_length = 255)
headerid = models.ForeignKey(header)

def __unicode__(self):
return self.id()

class options(models.Model):
opt_details = models.CharField(max_length = 255)
headerid = models.ForeignKey(header)

def __unicode__(self):
return self.id()


If there is a row in the database for table header as
Id=1, title=value-mart , createdby=CEO


How do I query criteria and options tables to get all the values related to header table
id=1

Also can some one please suggest a good link for queries examples.

Answer

First of all, don't use id in the names, because it is confusing. That field isn't the ID, it is the object itself. (If you have a field ref it automatically creates a field ref_id)

options.objects.filter(header=a_header)

You query it like any value, where some header instance is the value you are filtering on.

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