Project Help for Duplication of data

I am using mysql as my database and i am trying creating dropdown using a foreign key but i am getting problem of data duplication, as many times i upload datas in Requestion table(from my model below) in my database i get duplicate data in dropdown. and also i am not able to use distinct() in mysql.

class Purchase(models.Model):
supplier = models.ForeignKey(Supplier,on_delete=models.CASCADE,limit_choices_to={‘status’:True})
products = models.ForeignKey(Requesition,on_delete=models.CASCADE,limit_choices_to={‘status’:True})
quantity = models.IntegerField()
rate = models.IntegerField()
Total = models.IntegerField(null=True)
status = models.BooleanField(default=1)
select = models.BooleanField(default=0)

def __str__(self):
    return self.supplier.name

I think we’re going to see more details here, like the views in which you’re entering data into your Requesition model and the view generating and displaying this drop-down in which you’re seeing duplicates.

Also, when you say you upload data into the Requesition table, are you intending to replace an existing entry or are you intending to create multiple entries?