Django Model Save Triggering IntegrityError: Unique Constraint Violation on Multiple Fields
I'm dealing with I need help solving I'm wondering if anyone has experience with I'm working with an `IntegrityError` while trying to save a new instance of my Django model. The model has a unique constraint on a combination of two fields: `email` and `username`. However, when trying to create a new entry, I'm receiving the behavior: `django.db.utils.IntegrityError: UNIQUE constraint failed: myapp_mymodel.email, myapp_mymodel.username`. I've ensured that the values I'm trying to save are indeed unique, but I suspect there might be a race condition or a question with my save logic. Here's my model definition: ```python class MyModel(models.Model): email = models.EmailField(unique=True) username = models.CharField(max_length=150, unique=True) ``` In my view, I have the following logic to create a new instance: ```python from django.shortcuts import render, redirect from .models import MyModel from .forms import MyModelForm def create_entry(request): if request.method == 'POST': form = MyModelForm(request.POST) if form.is_valid(): form.save() return redirect('success') else: form = MyModelForm() return render(request, 'create_entry.html', {'form': form}) ``` I've also added a check to see if the email and username already exist before trying to save, like so: ```python if MyModel.objects.filter(email=email, username=username).exists(): # handle the duplicate case ``` Despite these precautions, I'm still getting the integrity behavior intermittently, particularly under load. Are there any best practices or patterns I can follow to avoid this situation? Could it be an scenario with concurrent requests? Any guidance would be greatly appreciated. My development environment is macOS. Any examples would be super helpful. For reference, this is a production web app. Is this even possible? For context: I'm using Python on CentOS. What's the best practice here?