How to apply advance django query set filters based on two different columns?-CodePudding

I am new to django. I am working on a test project. Where I have a Model CollectFee with structure given below:

class CollectFee(models.Model):
    boarder = models.ForeignKey(Boarder, on_delete=models.CASCADE)
    feetype = models.ForeignKey(FeeType, on_delete=models.CASCADE)
    amountdue = models.PositiveIntegerField("amount Due")
    amountpaid = models.PositiveIntegerField("amount Paid")
    balance = models.PositiveIntegerField("Balance")

    class Meta:
        verbose_name_plural = "Collect Fee"

    def __str__(self):
        return self.boarder.name

I want to apply a query set in the views which will display all the records where feetype_id is not 2, when this record is excluded then also exclude those records which have the same boarder_id as of already excluded record. For example, Exclude the second row as it has feetype_id = 2 then also exclude the third row because it has the same boarder_id as of second row.

As I am new, I was able to just implement the filter below:

def feedue(request):
    last_fee_type = FeeType.objects.last()
    boarders = CollectFee.objects.exclude(feetype_id=last_fee_type)
    
    context = {'boarders':boarders}
    return render(request, 'fee-due.html', context)

CodePudding user response：

You can exclude the many-to-one relationship with the through accessor like this:

CollectFee.objects.exclude(boarder__collectfee__feetype=last_fee_type)

This expression essentially gets the Boarder from a particular CollectFee object, then all CollectFees associated with that Boarder and their FeeTypes, allowing you to exclude accordingly.

CodePudding user response：

May be this helps

def feedue(request):
    excluded_objs = CollectFee.objects.filter(feetype_id=2)
    border_ids = [ids for obj.border_id in excluded_objs]
    duefee = CollectFee.objects.exclude(boarder_id__in=border_ids)

    context = {'duefee': duefee}
    return render(request, 'fee-due.html', context)