How could we multiple foreignkeys in intermediate table in Django.?

问题

I have M2M relationship table with an intermediate table along with multiple foreign keys such as Employee Designation and HRManagement. in it each employee has to be reported to one of the existed employees. How could I fix it please help me out in this scenario.

class Employee(models.Model):
    code = models.CharField(max_length = 256)
    designation =models.ManyToManyField(Designation,through = 'HRManagement',blank=True)
    status = models.BooleanField(default = True)
    join_date = models.DateField(default=datetime.datetime.now)
    leave_date = models.DateField(blank = True, null=True)
    username = models.CharField(max_length = 256)
    password = models.CharField(max_length = 256)
    first_name = models.CharField(max_length = 256)
    last_name = models.CharField(max_length = 256)
    address = models.TextField()

class Designation(models.Model):
    name = models.CharField(max_length = 256)

class HRManagement(models.Model):
    employee = models.ForeignKey(Employee, null=True,on_delete=models.CASCADE)
    designation = models.ForeignKey(Designation, on_delete=models.CASCADE,default=None,null=True)
    reportto = models.ForeignKey(Employee, null=True, related_name='reportto',on_delete=models.CASCADE)

thanks in advance.

来源：https://stackoverflow.com/questions/61298303/how-could-we-multiple-foreignkeys-in-intermediate-table-in-django