Django model use JSON file store to database

Question

I'm new to Python Django.I have model to load JSON file in my PostgreSQL database.When I migrate,getting some error message.

This URL is my JSON field: https://jsoneditoronline.org/#left=cloud.aabe0ab0f87349deada424286dc5c737

First, I create model to load JSON file.

from django.db import models

WEEKDAYS = [
        (1, ("Monday")),
        (2, ("Tuesday")),
        (3, ("Wednesday")),
        (4, ("Thursday")),
        (5, ("Friday")),
        (6, ("Saturday")),
        (7, ("Sunday")),
]

class BookStore(models.Model):
    cash_balance = models.FloatField(null=False)
    store_name = models.CharField(max_length=100, null =False)
    opening_hours = models.ManyToManyField('OpeningHours')


class Book(models.Model):
    books = models.ForeignKey(BookStore, on_delete=models.CASCADE)
    book_name = models.CharField(max_length=100, null=False)
    price = models.FloatField(null=False)

class OpeningHours(models.Model):
    week_day = models.CharField(max_length=20, choices=WEEKDAYS)
    start_min = models.TimeField()
    end_min = models.TimeField()

Then, I create 0002_load_json.py to loaddata jsondata.json in migrations directory

import os
from django.db import migrations
from django.core.management import call_command
from django.core import serializers

book_store_json_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '../../data'))
book_store_filename = 'book_store_data.json'

def load_book_store(apps, schema_editor):
    book_store_file = os.path.join(book_store_json_dir, book_store_filename)
    call_command('loaddata', book_store_file)
#    book_store = open(book_store_file, 'rb')
#    objects = serializers.deserialize('json', book_store, ignorenonexistent=True)
#    for obj in objects:
#        obj.save()
#    book_store.close()
#
def unload_book_store(apps, schema_editor):
    book_store_model = apps.get_model("bookstore_api", "model")
    book_store_model.objects.all().delete()

class Migration(migrations.Migration):

    dependencies = [
        ('bookstore_api', '0001_initial'),
    ]

    operations = [
            migrations.RunPython(load_book_store, reverse_code=unload_book_store),
    ]

When I execute manage.py migrate myapps, I get some error message.

django.core.serializers.base.DeserializationError: Problem installing fixture