How do I set up Django with PostgreSQL and optimize database performance?
I'm working on a Django project and encountering an issue with Django authentication. Here's my current implementation:
# models.py
from django.db import models
class UserProfile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
bio = models.TextField()
# Signal handler
@receiver(post_save, sender=User)
def create_profile(sender, instance, created, **kwargs):
if created:
UserProfile.objects.create(user=instance)
The specific error I'm getting is: "django.core.exceptions.ImproperlyConfigured: The SECRET_KEY setting must not be empty"
I've already tried the following approaches:
- Checked Django documentation and Stack Overflow
- Verified my database schema and migrations
- Added debugging prints to trace the issue
- Tested with different data inputs
Environment details:
- Django version: 5.0.1
- Python version: 3.11.0
- Database: PostgreSQL 15
- Operating system: Windows 11
Has anyone encountered this before? Any guidance would be greatly appreciated!
Comments
abaditaye: Excellent solution! This fixed my Django N+1 query problem immediately. Performance improved by 80%. 1 week, 4 days ago
azzani: Perfect! This JWT authentication setup works flawlessly with my React frontend. 1 week, 4 days ago
azzani: What about handling this in a Docker containerized environment? Any special considerations? 1 week, 4 days ago
3 Answers
The choice between Django signals and overriding save() depends on your use case:
Use save() method when:
- The logic is directly related to the model
- You need to modify the instance before saving
- The operation is essential for data integrity
class Article(models.Model):
title = models.CharField(max_length=200)
slug = models.SlugField(unique=True)
def save(self, *args, **kwargs):
if not self.slug:
self.slug = slugify(self.title)
super().save(*args, **kwargs)
Use signals when:
- You need decoupled logic
- Multiple models need the same behavior
- You're working with third-party models
from django.db.models.signals import post_save
from django.dispatch import receiver
@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
if created:
UserProfile.objects.create(user=instance)
Comments
james_ml: Could you provide the requirements.txt for the packages used in this solution? 1 week, 4 days ago
To handle Django database transactions properly and avoid data inconsistency, use Django's transaction management:
from django.db import transaction
# Method 1: Decorator
@transaction.atomic
def transfer_money(from_account, to_account, amount):
from_account.balance -= amount
from_account.save()
to_account.balance += amount
to_account.save()
# Method 2: Context manager
def complex_operation():
with transaction.atomic():
# All operations in this block are atomic
user = User.objects.create(username='test')
profile = UserProfile.objects.create(user=user)
# If any operation fails, all are rolled back
For more complex scenarios with savepoints:
def nested_transactions():
with transaction.atomic():
# Outer transaction
user = User.objects.create(username='test')
try:
with transaction.atomic():
# Inner transaction (savepoint)
risky_operation()
except Exception:
# Inner transaction rolled back, outer continues
handle_error()
This Django error typically occurs when you're trying to save a model instance that violates a unique constraint. Here's how to handle it properly:
from django.db import IntegrityError
from django.http import JsonResponse
try:
user = User.objects.create(
username=username,
email=email
)
except IntegrityError as e:
if 'username' in str(e):
return JsonResponse({'error': 'Username already exists'}, status=400)
elif 'email' in str(e):
return JsonResponse({'error': 'Email already exists'}, status=400)
else:
return JsonResponse({'error': 'Data integrity error'}, status=400)
Always use get_or_create() when you want to avoid duplicates:
user, created = User.objects.get_or_create(
username=username,
defaults={'email': email, 'first_name': first_name}
)
Comments
david_web: This threading vs multiprocessing explanation cleared up my confusion. Saved me hours of debugging! 1 week, 4 days ago
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