Thanks for the quick response Simon. Worked like a charm. -Don
On Tue, Jul 23, 2019 at 11:29 AM Simon Charette <charett...@gmail.com> wrote: > Hello Don, > > If you're on Django 2.2+ you should use bulk_update for this purpose[0] > > TestThing.objects.bulk_update(( > TestThing(id=id, value=new_value) > for id, value in new_values.items() > ), ['value']) > > Under the hood it performs a SQL query of the form > > UPDATE ... SET value = (CASE WHEN id=1 THEN foo WHEN id=2 THEN ...) > > That you can emulate yourself by using Case and When expressions if you're > using Django < 2.2. > > Cheers, > Simon > > [0] > https://docs.djangoproject.com/en/2.2/ref/models/querysets/#bulk-update > > Le mardi 23 juillet 2019 12:15:20 UTC-4, Don Baldwin a écrit : >> >> Hi, >> >> I have a dictionary where the key is the primary key from one of my >> database tables, and the values are the values that I want to update with. >> >> For example, I may have the following dictionary: >> >> new_values = {1:'a', 2:'b', 3:'c'} >> >> >> And the following model: >> >> class TestThing(models.Model): >> >> new_value = models.IntegerField(default=0) >> >> >> And I want to update the entry with primary key 1 with value 'a', etc. >> >> >> Note that there are other fields in the table that need to be preserved, so >> I can't just create a new table. >> >> >> Obviously, I could loop through each entry and update each entry >> individually, but this seems really inefficient, so I think there must be a >> better way to do this. >> >> >> Also, my table may have entries that aren't represented in my dictionary, so >> I don't think I can do the following: >> >> >> TestThing.objects.all().update(new_value=new_values[F(id)]) >> >> >> Thanks, >> >> Don >> >> -- > You received this message because you are subscribed to a topic in the > Google Groups "Django users" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/django-users/J79WXBWaNuA/unsubscribe. > To unsubscribe from this group and all its topics, 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/8fe0d69c-0158-4eaa-be5d-435a09a29535%40googlegroups.com > <https://groups.google.com/d/msgid/django-users/8fe0d69c-0158-4eaa-be5d-435a09a29535%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-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAKL%3DYPEHGoBq6MH%2BZQoa0sY6P2tdcFD3anVZ0dOMeUT__jrdrw%40mail.gmail.com.
