in backend/model_garden/migrations/0015_labelingtask_task_id.py [0:0]
def set_task_id(apps, schema_editor):
LabelingTask = apps.get_model('model_garden', 'LabelingTask')
for labeling_task in LabelingTask.objects.all().iterator():
if labeling_task.url:
labeling_task.task_id = labeling_task.url.split('/')[-1]
labeling_task.save()
else:
labeling_task.delete()