Is there a way to delete all Events?

[LaundroMat]

I'd like to reset the logging I'm using pghistory for because some of the models don't exist anymore and some model instances were deleted. How can I delete the full history or all Events?

[wesleykendall]

There are a few ways to do this:

1. If the model still exists in your code base:

   from myapp.models import MyModel
   
   for event_model in MyModel.pgh_event_models.values():
       event_model.objects.all().delete()

   Note - Use from django.apps import apps and then iterate over every model with apps.get_models. Any model with the pgh_event_models attribute has history models

2. If the model no longer exists:

   Your best option here is raw SQL. Find the table name of the event model (usually it's the model's table name plus _event) and then do:

   from django.db import connection
   
   with connection.cursor() as cursor:
       cursor.execute("DELETE FROM my_event_model_table")

Note, if you're using append_only=True or PGHISTORY_APPEND_ONLY=True and the models are still in your codebase, you'll need to ignore the protection triggers:

import pgtrigger

with pgtrigger.ignore("app_label.MyModelEvent:append_only"):
    ...

Finally, django-pghistory disables cascading deletion behavior by default. If you'd like change this globally, do this in your settings:

import pghistory

PGHISTORY_OBJ_FIELD = pghistory.ObjForeignKey(on_delete=models.CASCADE)

This can also be supplied to @pghistory.track(obj_field=...) for individual models