Django supports model inheritance, allowing you to create base models that share common fields or logic across multiple related models. There are two main types of model inheritance in Django:

1. Abstract base classes – used for reusing common fields and methods across models without creating a separate database table.
2. Multi-table inheritance – used when you want each model in the inheritance chain to have its own table in the database.

🔹 1. Abstract Base Classes

Use this when you want to define shared fields and behavior in a parent class, but don’t want a separate table for that class in the database.

✅ Example:

```python line_numbers from django.db import models

class TimestampedModel(models.Model): created_at = models.DateTimeField(auto_now_add=True) updated_at = models.DateTimeField(auto_now=True)

class Meta:
    abstract = True

class BlogPost(TimestampedModel): title = models.CharField(max_length=200) content = models.TextField()

class Comment(TimestampedModel): post = models.ForeignKey(BlogPost, on_delete=models.CASCADE) text = models.TextField()

* `TimestampedModel` is abstract → no table is created for it.
* Both `BlogPost` and `Comment` get the `created_at` and `updated_at` fields.
* Ideal for **shared fields**, **custom methods**, or **common logic**.

---

### 🔹 2. Multi-Table Inheritance

Use this when each model in the hierarchy should have **its own table** and you want to preserve a **parent-child relationship** at the database level.

#### ✅ Example:

```python
class Content(models.Model):
    title = models.CharField(max_length=100)

class BlogPost(Content):
    body = models.TextField()

class Video(Content):
    video_url = models.URLField()

• Content has its own table.
• BlogPost and Video each have separate tables with a OneToOne link to Content.
• When you access a BlogPost, Django queries both the blogpost and content tables.
• This is useful when you need polymorphic-like behavior, e.g., all Content items share a title but have different specific fields.

🔹 Differences and When to Use Each

| Feature | Abstract Base | Multi-Table | | ----------------------------- | ------------- | --------------------- | | Database table for parent | ❌ No | ✅ Yes | | Shared fields across children | ✅ Yes | ✅ Yes | | Suitable for code reuse only | ✅ Yes | ❌ No | | Suitable for polymorphic data | ❌ No | ✅ Yes | | Performance (simpler queries) | ✅ Better | ❌ Slower due to joins |

🧠 How to Apply This in Your Projects

• Use abstract base classes to avoid repeating common fields and methods (e.g., timestamps, slugs, authorship).
• Use multi-table inheritance when multiple models share a core identity but add different fields (e.g., different types of content or products).
• Always add class Meta: abstract = True if you don’t want a database table for the parent.
• Avoid multiple levels of multi-table inheritance unless you have a strong use case—it can become hard to query and manage.

Model inheritance gives you a powerful tool for structuring your data models more cleanly and avoiding redundancy while maintaining flexibility in database design.