Its unclear what you mean by "last ID" - and I cannot see the value of storing such as they are available in the database...
But have a look at https://stackoverflow.com/questions/12649659/how-to-set-a-django-model-fields-default-value-to-a-function-call-callable-e The example is: from datetime import datetime, timedelta # default to 1 day from now def get_default_my_date(): return datetime.now() + timedelta(days=1) class MyModel(models.Model): my_date = models.DateTimeField(default=get_default_my_date) Instead of the date arithmetic, you'd need to write code to, for example, extract last ID from the database (assuming you have an auto-increment ID set) and do the concatenation. On Thursday, 7 May 2020 02:23:22 UTC+2, Anselme SERI wrote: > > Thanks you for your answer. I know how to make a default value in > charfield but I don't know how to build function which returns value for > my default field. In my case this function must retrieve last id on my > model and must concataned it with a string and the final result must be > affected to default charfield. Have you an example ? Help me plz. > > Le mer. 6 mai 2020 à 18:44, Motaz Hejaze <trap...@gmail.com <javascript:>> > a écrit : > >> Yes you can make a normal charfield and assign its default attribute to a >> function you declare >> >> On Wed, 6 May 2020, 6:53 pm Anselme SERI, <anselme...@gmail.com >> <javascript:>> wrote: >> >>> Hi, >>> >>> I use Django 3.0 and I would like to create a function which fill >>> automatically a field in my models. >>> Can I do it directly in models.py ? How? >>> >>> Thanks a lot >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Django users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to django...@googlegroups.com <javascript:>. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-users/5f810453-c7ca-4c10-bca1-4cfe11ea496a%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/django-users/5f810453-c7ca-4c10-bca1-4cfe11ea496a%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to django...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/CAHV4E-dDRD%3DLteuDo7KuATzjKem-ThvtozzHuaqkwAeAC%2BBrZw%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/django-users/CAHV4E-dDRD%3DLteuDo7KuATzjKem-ThvtozzHuaqkwAeAC%2BBrZw%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/48c4d59e-8241-4739-b8df-feab45a7fa3a%40googlegroups.com.
