What are Django migrations and how do they work?

Question

Accepted Answer

**Django migrations** track and apply **database schema changes**.

```bash
# Create migrations after model changes
python manage.py makemigrations

# Apply all pending migrations
python manage.py migrate

# Show migration status
python manage.py showmigrations

# Rollback to specific migration
python manage.py migrate app_name 0003

# Create migration with custom SQL
python manage.py makemigrations --empty app_name
```

**Migration file:**
```python
# 0001_initial.py
from django.db import migrations, models

class Migration(migrations.Migration):
    initial = True

dependencies = [
        ("auth", "0012_alter_user_first_name_max_length"),
    ]

operations = [
        migrations.CreateModel(
            name="Article",
            fields=[
                ("id", models.AutoField(primary_key=True)),
                ("title", models.CharField(max_length=200)),
                ("content", models.TextField()),
            ],
        ),
    ]
```

**Best practices:**
- Review migrations before applying.
- Don't edit applied migrations.
- Use `squashmigrations` to clean up history.

Python: What are Django migrations and how do they work?