I have set up a Django app that queries from a PostgreSQL database. Exporting all the data within a model seems relatively straight forward but what if I wanted to export only the data from a returned queryset.
Currently I'm managing this by having a button on my page and changing the url when the user wishes to export data. The code within the view that I'm rendering is as follows.
def export_data(request,pk):
resource_class = MDPResource()
queryset = MDP.objects.filter(mdp_id=pk)
dataset = person_resource.export(queryset)
response = HttpResponse(dataset.csv, content_type='text/csv')
response['Content-Disposition'] = 'attachment; filename="mdpbasic.csv"'
return response
However, this means that I'm going to be making one query when the user initially opens the page and then a second query (in effect 2 extra) when the user wishes to export the data which I have already queried for in the previous view.
Moreover, in a section of my page I'm also using Q models for complex filtering. The above method is not sufficient for exporting data in that case (I don't want to have to reconstruct the query).
I also do not want to have to write the data to a file (if I can help it) because then that raises the issue of having to delete it using os once the user has exported their data.
Generating CSV file with Django (dynamic content)
I have already checked out this question but I'm not sure how passing a dictionary to a urlpattern works and it still seems as though the query is being made one more time anyways (still one less than my current method).
I don't know if I should be checking out apps for this particular purpose. I've looked into a couple such as django-queryset-csv and django-import-export but none of them seem to do what I've mentioned.
django: export current queryset to csv by button click in browser
I've seen this example that makes use of class-based views but I wanted to see if there was a way to do it with function-based views so I don't have to migrate all my views to class-based ones.
