База данных django TypeError
Я пытаюсь создать многомандатное поле, все идет хорошо, но когда я создаю отдел и назначаю пользователя (Ids), я получаю ошибку
Поле 'id' ожидало число, но получило <Id: luka>.
from django.db import models
# Create your models here.
class Id(models.Model):
    first_name = models.CharField(max_length=100, null=True)
    last_name = models.CharField(max_length=100, null=True)
    date_of_birth = models.CharField(max_length=100, null=True)
    date_of_expire = models.CharField(max_length=100, null=True)
    date_of_issue = models.CharField(max_length=100, null=True)
    CHOICES = [('Male', 'Female'),
               ('Female', 'Male')]
    gender = models.CharField(max_length=30, choices=CHOICES)
    # gender = models.CharField(max_length=10)
    address = models.TextField(null=True)
    country = models.CharField(max_length=30,null=True)
    city = models.CharField(max_length=30,null=True)
    card_no = models.CharField(max_length=30,null=True)
    personal_number = models.CharField(max_length=30,null=True)
    image = models.ImageField(default='defaut.jpg', upload_to='document_pics')
    def __str__(self):
        return self.first_name
class Departments(models.Model):
    name = models.CharField(max_length=30, null=True)
    users = models.ManyToManyField(Id)
    def __str__(self):
        return self.name