Django DateTimeField with auto_now_add asks for default

Question

I have this field in my model created_at = models.DateTimeField( auto_now_add = True )

When I try to make migrations I get an error:

You are trying to add the field 'created_at' with 'auto_now_add=True' to user wi
thout a default; the database needs something to populate existing rows.

 1) Provide a one-off default now (will be set on all existing rows)
 2) Quit, and let me add a default in models.py

I tried to set the default value but it says default and auto_now_add are mutually exclusive. Of course I could just use default without auto_now_add but I want to know why this error pops up. Did I miss something?

Answer 1

Delete the migration file in app and you can makemigrtion process at the time no error raises, It raises due to the reason of previously created time object.