from django.db import models

class Snap(models.Model):
    filename = models.CharField(max_length=128)
    username = models.CharField(max_length=128)
    downloaded = models.DateTimeField(auto_now_add=True)


@@ -73,32 +73,50 @@
 odels.CharField(
+primary_key=True, 
 max_length=128)%0A

make filename primary key