I just updated my python from 3.9.1 to 3.9.4. When I tried to run the server. The console gave me a warning for this:
WARNINGS:
learning_logs.Entry: (models.W042) Auto-created primary key used when not defining a primary key type, by default 'django.db.models.AutoField'.
HINT: Configure the DEFAULT_AUTO_FIELD setting or the LearningLogsConfig.default_auto_field attribute to point to a subclass of AutoField, e.g. 'django.db.models.BigAutoField'.
learning_logs.Topic: (models.W042) Auto-created primary key used when not defining a primary key type, by default 'django.db.models.AutoField'.
HINT: Configure the DEFAULT_AUTO_FIELD setting or the LearningLogsConfig.default_auto_field attribute to point to a subclass of AutoField, e.g. 'django.db.models.BigAutoField'.
No changes detected in app 'learning_logs'
May I please know how do I fix this. I read the documentation about this, but I don't understand how this part this page relates to this.
Models.py
from django.db import models
from django.contrib.auth.models import User
# Create your models here.
class Topic(models.Model):
text = models.CharField(max_length = 200)
date_added = models.DateTimeField(auto_now_add = True)
image = models.ImageField(upload_to = 'backgroud_images', null = True, blank = True)
owner = models.ForeignKey(User,on_delete = models.CASCADE)
def __str__(self):
return self.text
class Entry(models.Model):
topic = models.ForeignKey(Topic,on_delete = models.CASCADE)
text = models.TextField()
date_added = models.DateTimeField(auto_now_add = True)
class Meta:
verbose_name_plural = "Entries"
def __str__(self):
return self.text[:50]
Your models do not have primary keys. But they are being created automatically by django.
You need to choose type of auto-created primary keys https://docs.djangoproject.com/en/3.2/releases/3.2/#customizing-type-of-auto-created-primary-keys (new in Django 3.2)
Either add this into settings.py
DEFAULT_AUTO_FIELD='django.db.models.AutoField'
or
class Topic(models.Model):
id = models.AutoField(primary_key=True)
...
You have unintentionaly updated Django to 3.2 which warns you and as hint text suggest you have to set DEFAULT_AUTO_FIELD as documented
This way you avoid unwanted migrations in future releases as
value of DEFAULT_AUTO_FIELD will be changed to BigAutoField
You should set DEFAULT_AUTO_FIELD explicitly to current DEFAULT_AUTO_FIELD value
DEFAULT_AUTO_FIELD = 'django.db.models.AutoField'
you could configure it even per app basis ( if you expect to build new apps with current style primary key)
from django.apps import AppConfig class MyAppConfig(AppConfig): default_auto_field = 'django.db.models.AutoField' name = 'my_app'
or even per-model (discouraged)
from django.db import models class MyModel(models.Model): id = models.AutoField(primary_key=True)
You should also take care of version locking your requirements as you could introduce backward incompatible changes in production
new created project settings.py file in django 3.2
includes this:
..
# Default primary key field type
# https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field
DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
and as your project was created on earlier versions of django so you can append this to your settings.