Django search objects by multiple keys - django

Question

I am trying to prepare search form where user is able to type 1, 2 or all (3 in this case) search filters.
Lets say that search filters are:
last name, phone and address. I am trying to filter queryset by:
if filterForm.is_valid():
last_name = filterForm.cleaned_data.get('last_name')
phone= filterForm.cleaned_data.get('phone')
address = filterForm.cleaned_data.get('address')
if last_name is None and phone is None and address is None:
pass
#we dont do search id db
else:
clients = Client.objects.filter(Q(last_name__contains=last_name) | Q(phone=phone) | Q(address__contains=address))
Each search key may be blank.
Unfortunately, it returns more results then expected. When I type in search filter "Example" as last name field, it returns all fields with this last name + many others rows.
Any idea how to fix this search issue?

Answer 1

I believe that your search returns more results than expected when any of the search keys are blank since a blank key will match any row with a value.
By only filtering on keys that contains a value it should work better.
Here is one example of how it can be done:
if filterForm.is_valid():
last_name = filterForm.cleaned_data.get('last_name')
phone= filterForm.cleaned_data.get('phone')
address = filterForm.cleaned_data.get('address')
import operator
predicates = []
if last_name:
predicates.append(Q(last_name__contains=last_name))
if phone:
predicates.append(Q(phone=phone))
if address:
predicates.append(Q(address__contains=address))
if len(predicates) == 0:
# Nothing to search for
pass
else:
clients = Client.objects.filter(reduce(operator.or_, predicates))
The code above will dynamically add filters that shall be added to the query. The usage of oprator.or_ will concatenate the statements with OR (=at least one statement needs to be satisfied). If you instead want all statements to be satisfied you can use operator.and_ instead.