Cannot query "ABC": Must be "Image" instance - django

Question

I came across an error message within the model.py. I would appreciate if you guys could give me some assistance on this; the following are parts of the model.py:
class WorkJob(models.Model):
id = models.AutoField(primary_key=True)
share = models.ForeignKey(FShare, on_delete=models.PROTECT)
aftId = models.ForeignKey(AftId, null=True, blank=True, on_delete=models.PROTECT)
history = HistoricalRecords()
def __str__(self):
if self.aftId:
return self.aftId.aft
else:
return str('AFT-NA')
class Image(models.Model):
id = models.AutoField(primary_key=True)
imagingJob = models.OneToOneField(WorkJob, on_delete=models.PROTECT)
md5 = models.CharField(max_length=32, null=True, blank=True)
originalCopy = models.ForeignKey(Disc, related_name='originalCopy', null=True, blank=True, on_delete=models.PROTECT)
workingCopy = models.ForeignKey(Disc, related_name='workingCopy', null=True, blank=True, on_delete=models.PROTECT)
history = HistoricalRecords()
def __str__(self):
return self.imagingJob.fileShare.identifier
class Copy(models.Model):
id = models.AutoField(primary_key=True)
image = models.ForeignKey(Image, on_delete=models.PROTECT)
disc = models.ForeignKey(Disc, on_delete=models.PROTECT, related_name='copy')
history = HistoricalRecords()
def aftId(self):
return self.image.imagingJob.aftId.aft
the next class is the one that I have problems.
class TFI(models.Model):
id = models.AutoField(primary_key=True)
createDate = models.DateTimeField(auto_now_add=True, null=True)
status = models.IntegerField(choices=STATUS_OPTIONS, default=0)
history = HistoricalRecords()
def check_third(self):
if self.status == 5:
im = 0
third_imajob = WorkJob.objects.filter(share=self.share)
for ima in third_imajob:
if Copy.objects.filter(image__exact=ima.aftId).exists():
# some code blablabla
else:
break
The line that the error message says that it is problematic is:
if Copy.objects.filter(image__exact=ima.aftId).exists():
I am not certain why is it saying that the instance must be with Image. The line clearly is extracting from class Copy and WorkJob. I did see that that the Copy.image has a foreignkey reference to class Image but I am not certain how to troubleshoot this. Thanks in advance!
EDIT: following is also a part of the code and the above code has also been added.
class AftId(models.Model):
id = models.AutoField(unique=True, primary_key=True)
aft = models.CharField(unique=True, max_length=30)
assignedTo = models.ForeignKey(settings.AUTH_USER_MODEL, null=True, on_delete=models.PROTECT)
history = HistoricalRecords()
def __str__(self):
return self.aft

Answer 1

You are trying to compare some aftID instances and Image.
I can't see your aftId model but I guess it has an image foreign key field, so your query should be Copy.objects.filter(image__exact=ima.aftId.image).exists()