[Python] Django-Simple-History: Avoid Redundant History Records & Track Generic Relations

We are using django-simple-history to track changes in our models, including many-to-many (m2m) relationships and generic relationships.

Model:

class BandProfile(BaseModel):

class Meta:
db_table = "band_profiles"

name = models.CharField(max_length=255)
types = models.ManyToManyField(
Choices,
related_name="types",
limit_choices_to={"category": "type"},
blank=True,
)
description = models.TextField(null=True, blank=True)

history = HistoricalRecords(
table_name="history_band_profiles",
history_user_setter=set_historical_user_from_request,
history_user_getter=get_historical_user_from_request,
history_user_id_field=models.CharField(max_length=36, null=True),
m2m_fields=[types], # Many-to-many tracking
)

def __str__(self):
return f"Band Profile for {self.name}"


Serializer:

def create(self, validated_data):
"""
Create method for BandProfile with handling for related fields.
"""
types = validated_data.pop("type_ids", [])

band_profile = BandProfile.objects.create(**validated_data)
band_profile.types.set(types)


Issues:

When creating or updating resources, django-simple-history is generating multiple redundant history entries, which results in incorrect historical tracking.

Below shows the redundant records.

See the redundant records

Expected Response Format: We need a structured response that includes the historical records of the resource, its many-to-many relations, and generic relations, like this (Field names are examples):

[
{
"id": 101,
"name": "Resource A",
"history_date": "2025-03-20T10:00:00Z",
"change_type": "update",
"types": [
{
"id": 201,
"name": "Sector X",
"history_date": "2025-03-19T15:00:00Z",
"change_type": "create"
},
{
"id": 202,
"name": "Sector Y",
"history_date": "2025-03-20T16:00:00Z",
"change_type": "update"
}
],
"generic_relation": [
{
"id": 301,
"type": "Document",
"title": "Policy Document A",
"history_date": "2025-03-18T11:00:00Z",
"change_type": "create"
},
{
"id": 302,
"type": "Document",
"title": "Policy Document B",
"history_date": "2025-03-20T14:00:00Z",
"change_type": "delete"
}
]
}
]

Questions:


How can we prevent redundant history records when creating and updating with many-to-many relationships? Are we missing something in our configuration?

Notes:

• We tried using a through model for many-to-many relationships, but the history records do not maintain a link between the main model and the related objects

Continue reading...