# Django Error

## fields.E304 Reverse accessor clashes in Django

같은 클래스를 ForeignKey로 사용할 경우에 발생
-> `related_name` 설정으로 해결

<code>
create_user = models.ForeignKey(User, related_name='%(class)s_requests_created')
</code>

```py
class Follow(BaseModel):
    """팔로우"""
    from_user = models.ForeignKey(User, related_name='from_user', on_delete=models.CASCADE)
    to_user = models.ForeignKey(User, related_name='to_user', on_delete=models.CASCADE)
    
```

## Django migration error :you cannot alter to or from M2M fields, or add or remove through= on M2M fields

migration 파일에서 AlterField 부분을, RemoveField, AddField로 분리한다.

```
# migrations.AlterField(
#     model_name='product',
#     name='tags',
#     field=models.ManyToManyField(through='brand.ProductTag', to='brand.Tag'),
# ),
migrations.RemoveField(
    model_name='product',
    name='tags',
),
migrations.AddField(
    model_name='product',
    name='tags',
    field=models.ManyToManyField(through='brand.ProductTag', to='brand.Tag'),
),
```