Update from CSV

I have a CSV file with some values I exported from a production database. I'd like to import them into another database overwriting any conflicting rows using the import wizard. Something along the lines of

insert into foo (a, b, c) values (1, 2, 3) on conflict (a) do update set a = 1, b = 2, c = 3

But you know, automated.

Is that possible?