[Django]-Django Model – Get distinct value list

Perhaps you might want to go with this:

Entity.objects.order_by().values_list('foreign_key', flat=True).distinct()

Entity.objects.values_list('foreign_key', flat=True).distinct().order_by()

distinct does not work without order_by, as explained in Django documentation:

Any fields used in an order_by() call are included in the SQL SELECT
columns. This can sometimes lead to unexpected results when used in
conjunction with distinct(). If you order by fields from a related
model, those fields will be added to the selected columns and they may
make otherwise duplicate rows appear to be distinct. Since the extra
columns don’t appear in the returned results (they are only there to
support ordering), it sometimes looks like non-distinct results are
being returned.

Similarly, if you use a values() query to restrict the columns
selected, the columns used in any order_by() (or default model
ordering) will still be involved and may affect uniqueness of the
results.

The moral here is that if you are using distinct() be careful about
ordering by related models. Similarly, when using distinct() and
values() together, be careful when ordering by fields not in the
values() call.

Entity.objects.order_by('foreign_key').distinct('foreign_key')

If you already have them as a list, then convert it to a set() to get the distinct values.