django-orm

django-orm Best Practices

These rules are your definitive guide for writing robust and performant Django ORM code. Adhere to them strictly to ensure consistency, efficiency, and maintainability across our projects.

1. Model Structure and Naming Conventions

Always follow the official Django style guide for models. Consistency is paramount.

• Naming:
  • Models: PascalCase and singular.
  • Fields: snake_case.
• Ordering: Maintain a consistent order within your model definitions.

# ❌ BAD: Inconsistent naming, poor ordering
from django.db import models

class books(models.Model):
    BookTitle = models.CharField(max_length=200)
    author_name = models.CharField(max_length=100)
    def __str__(self):
        return self.BookTitle
    class Meta:
        ordering = ['BookTitle']

# ✅ GOOD: Adheres to conventions
from django.db import models
from django.urls import reverse

class Book(models.Model):
    # 1. Choices (if any)
    class Status(models.TextChoices):
        DRAFT = "DR", "Draft"
        PUBLISHED = "PB", "Published"

    # 2. Database Fields
    title = models.CharField(max_length=200, verbose_name="Book Title")
    author = models.ForeignKey('Author', on_delete=models.CASCADE, related_name="books")
    status = models.CharField(max_length=2, choices=Status.choices, default=Status.DRAFT)
    created_at = models.DateTimeField(auto_now_add=True)

    # 3. Custom Managers (if any)
    # objects = BookManager()

    # 4. Meta class
    class Meta:
        verbose_name = "book"
        verbose_name_plural = "books"
        ordering = ["-created_at", "title"] # Default ordering
        indexes = [
            models.Index(fields=['title']),
            models.Index(fields=['author', 'status']),
        ]

    # 5. __str__ method
    def __str__(self):
        return f"{self.title} by {self.author.name}"

    # 6. save() method (if overridden)
    # def save(self, *args, **kwargs):
    #     super().save(*args, **kwargs)

    # 7. get_absolute_url() method
    def get_absolute_url(self):
        return reverse("book_detail", args=[str(self.id)])

    # 8. Custom methods (if any)
    def is_published(self):
        return self.status == self.Status.PUBLISHED