Thanks Alex, that's really helpful and I'm certainly closer now! However, after a fair bit of experimenting with that exclude() method, I still can't quite get it to do what I need.
I'm trying to get a list of all employees who do not have a qualification of a certain type (which I'llcall 'A1'). I can get a list of those who do have the qualification by using a lookup on the related "Qualification" model as follows: Employee.objects.filter(qualification__type__exact='A1') Essentially, what I need is a list of all Employees, minus the names on that filtered list. If I use the exclude() method on the same lookup (so, Employee.objects.exclude(qualification__type__exact='A1')), the query returns those employees who have a qualification of any type other than A1. It doesn't include the employees who have no qualifications at all, and it *does* include the ones who have A1 as well as other qualifications. Can anyone suggest what I'm doing wrong? Thanks, Bianca On Apr 20, 10:54 am, Alex Gaynor <alex.gay...@gmail.com> wrote: > On Sun, Apr 19, 2009 at 8:48 PM, bweiss <weissmanbia...@gmail.com> wrote: > > > I'm working on a database project which controls details related to > > the employees of a company. > > > It includes a table called "Qualifications", which has details of all > > the industry certifications and training courses obtained by > > employees. This table is connected via ForeignKey fields to two other > > tables - "Employees", which has the names and other basic details of > > the employees, and "Qualification Types", which has the names and > > other information about the training courses (eg. name, certifying > > body, etc etc). > > > So to enter a Qualification obtained, users choose a name from the > > data in the Employee table, and a Qualification Type from the data in > > that table, and then enter the remaining details (eg. date obtained, > > expiry date). > > > Until now I've only written fairly basic views - requests that will > > find a list of qualifications of type X, or belonging to employee Y, > > or expiring in month Z. > > > Now I'm trying to write a request view that will find the employees > > that DON'T have an associated qualification of a particular type. > > > I'm really struggling with how to perform this sort of "negative" > > filtering on related objects. > > > Can anyone tell me if this is even possible, and if so, how I might go > > about it? > > > Many thanks in advance for any help, > > > BWeiss > > If I follow correctly you're just looking to do the opposite of what you're > already doing, so far you using the filter() method, so what you need is the > opposite of that. Luckily we have just the thing! The exclude() > method,http://docs.djangoproject.com/en/dev/ref/models/querysets/#exclude-kw... > > Alex > > -- > "I disapprove of what you say, but I will defend to the death your right to > say it." --Voltaire > "The people's good is the highest law."--Cicero --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
