TypeError：int（）参数必须是字符串或数字，而不是'Model Instance'-Heroku

Question

Trying to deploy my project on the server, and i'm stuck in migrations becouse there is some error:

  File "/app/.heroku/python/lib/python2.7/site-packages/django/db/backends/base/schema.py", line 382, in add_field
definition, params = self.column_sql(model, field, include_default=True)
  File "/app/.heroku/python/lib/python2.7/site-packages/django/db/backends/base/schema.py", line 145, in column_sql
default_value = self.effective_default(field)
  File "/app/.heroku/python/lib/python2.7/site-packages/django/db/backends/base/schema.py", line 210, in effective_default
default = field.get_db_prep_save(default, self.connection)
  File "/app/.heroku/python/lib/python2.7/site-packages/django/db/models/fields/related.py", line 915, in get_db_prep_save
return self.target_field.get_db_prep_save(value, connection=connection)
File "/app/.heroku/python/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 728, in get_db_prep_save
prepared=False)
File "/app/.heroku/python/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 968, in get_db_prep_value
value = self.get_prep_value(value)
File "/app/.heroku/python/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 976, in get_prep_value
return int(value)
TypeError: int() argument must be a string or a number, not 'Profile'

And here is my models.py file:

class Post(models.Model):
author = models.ForeignKey('auth.User')
title = models.CharField(max_length=75)
image = models.ImageField(null=True, blank=True, width_field="width_field", height_field="height_field", upload_to='images') #must be installed Pillow for ImageField
height_field = models.IntegerField(default=0)
width_field = models.IntegerField(default=0)
content = models.TextField()
updated = models.DateTimeField(default=datetime.now())
timestamp = models.DateTimeField(default=datetime.now())


def __str__(self):
    return self.title

@receiver(pre_delete, sender=Post)
def post_delete(sender, instance, **kwargs):
# Pass false so FileField doesn't save the model.
if instance.image:
    instance.image.delete(False)




class Profile(models.Model):
onlyletters = RegexValidator(r'^[a-zA-Z]*$', 'Only letters are allowed.')
author = models.ForeignKey('auth.User')
name = models.CharField(max_length=20, null = True, validators=[onlyletters])
surname = models.CharField(max_length=25, null = True, validators=[onlyletters])
city = models.CharField(max_length=30, blank=True, validators=[onlyletters])
birth_date = models.DateField(blank=True, null=True, help_text="Can not be more than 100 years - (Format yyyy-mm-dd)")

topic = models.CharField(max_length = 50, null=True)


def __str__(self):
    return self.topic

class Favourite(models.Model):
name = models.CharField(max_length=50)
members = models.ManyToManyField(Profile, through='Membership')

def __str__(self):              # __unicode__ on Python 2
    return self.name


class Membership(models.Model):
author = models.CharField(max_length=50)
profile = models.ForeignKey(Profile, default=Profile)
favourite = models.ForeignKey(Favourite)
created = models.DateTimeField(default=timezone.now)



class Comment(models.Model):
post = models.ForeignKey('blogapp.Post', related_name='comments')
author = models.ForeignKey('auth.User')
text = models.TextField()
created_date = models.DateTimeField(default=timezone.now)

def __str__(self):
    return self.text

Just trying to make some fresh app on heroku, making new migrations and deleting olders but it's still didn't work. Can anybody know what's wrong with it? Thanks for the answer.

Answer 1

Here's the culprit:

profile = models.ForeignKey(Profile, default=Profile)
#                                    ^^^^^^^^^^^^^^^

You can't set a Model class as a Foreignkey default. If you're thinking of setting an hardcoded default then you should use an int and be sure the selected value exists as a key in your Profile model.