On Wed, Feb 22, 2012 at 01:15:04PM -0800, gowthaman ramasamy wrote:
I am trying to construct the following query at the end. Result.objects.filter(Q(analysis__experiment__experiment_code="PyLS24") |Q(analysis__experiment__experiment_code="PyLS40"))How I do now: The values are passed from a from(post) using checkboxes (#expcodes = request.POST.getlist('expcode') ). So I get a list of: expcodes = ['PyLS24', 'PyLS40'] then use the for loop to construct string representation of Q object. expcodes = ['PyLS24', 'PyLS40'] k='' c=0 for e in expcodes: j=e.join(['Q(analysis__experiment__experiment_code="','") ']) if c == 0: k = j else: k='|'.join([k, j]) c = c+1 k in this gives me 'Q(analysis__experiment__experiment_code="PyLS24") |Q(analysis__experiment__experiment_code="PyLS40") '. When i use this to query the model as following... Result.objects.filter(k)I get "ValueError: too many values to unpack" error. But, exact string, if I copy paste into Results.object.filter(here) it works. When I checked the type, k constructed from for loop is in string format (obviously). But, when I copy paste the pint out of k, it automatically becomes Django's Q object.
The issue is that you can't use a string to generate the Q object passed to filter(). Instead, you need to build them up in a list, and then use the bitwise-OR operator. You can either do that in a loop, or this way:
import operator q_objs = [ Q(analysis__experiment__experiment_code=code) for code in expcodes ] arg = reduce(operator.or_, q_objs) # do bitwise-OR of all objects in the list Results.object.filter(arg) -- 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.
