How to implement raw sql query in Tastypie - tastypie

Question

I am trying to do this simple query, but it does not work. Thanks.
SELECT * FROM TSimple where (start_date < '2012-04-20' and end_date is null) or
(end_date > '2012-04-20' and start_date < '2012-04-20')
class TSimple (models.Model):
start_date = models.DateTimeField()
end_date = models.DateTimeField(blank=True, null=True)
...
class TSimpleResource(ModelResource):
def dehydrate(self, bundle):
request_method = bundle.request.META['REQUEST_METHOD']
if request_method=='GET':
new_date = bundle.request.GET.get('new_date', '')
qs = TSimple.objects.raw(
'SELECT * FROM TSimple where (start_date<=\'' +
new_date + '\' and end_date>=\'' +
new_date + '\') or (start_date<=\'' + new_date +
'\' and end_date is null)')
ret_list = [row for row in qs]
// NOT WORK. Not able to get correct json data in javascript.
// It needs return bundle. HOW to replace bundle?
// Is this correct way to do it?
return ret_list
else:
// This is ok.
return bundle
I have following questions:
1) (raw sql method) If implementing in dehydrate method is correct way to do it? If it is, above does not work. It should return bundle object. How to construct new bundle?
If above method is ok, I noticed that bundle already constructed .data field with default query(?), which will be thrown away with new query. That raise the questions if this is right way to do it.
2) If there are other raw sql method to do it? Where to execute the sql?
3) How to do it in filter?
4) I know sql and not familiar with complex filter. That's why I am trying to use raw sql method to do quick prototype. What are the draw back? I noticed that using Tastypie has many unnecessary queries which I don't know how to get rid of it. Example, query on table with foreign key trigger query to another table's data, which I don't want to get.

Answer 1

I figure out the filter and it seems worked. But I am still interested in raw sql.
def apply_filters(self, request, applicable_filters):
base_filter = super(TSimpleResource, self).apply_filters(request,
applicable_filters)
new_date = request.GET.get('new_date', None)
if new_date:
qset = (
(
Q(start_date__lte=new_date) &
Q(end_date__gte=new_date)
) |
(
Q(start_date__lte=new_date) &
Q(end_date__isnull=True)
)
)
base_filter = base_filter.filter(qset)
return base_filter