带有 __in 查找的 django icontains

Question

So I want to find any kind of matching given some fields, so for example, this is what I would like to do:

possible_merchants = ["amazon", "web", "services"]
# Possible name --> "Amazon Service"
Companies.objects.filter(name__icontains__in=possible_merchants)

sadly it is not possible to mix icontains and the __in lookup.

It seems to be a pretty complex query so if at least I could ignore case the name that would be enough, for example:

Companies.objects.filter(name__ignorecase__in=possible_merchants)

Any ideas?

PD: The queries I posted don't work, it's just a way to express what I need (just in case heh)

Answer 1

You can create querysets with the Q constructor and combine them with the | operator to get their union:

from django.db.models import Q

def companies_matching(merchants):
    """
    Return a queryset for companies whose names contain case-insensitive
    matches for any of the `merchants`.
    """
    q = Q()
    for merchant in merchants:
        q |= Q(name__icontains = merchant)
    return Companies.objects.filter(q)

(And similarly with iexact instead of icontains .)

Answer 2

I find it a cleaner approach using reduce and or_ operator:

from django.db.models import Q
from functools import reduce
from operator import or_

def get_companies_from_merchants(merchant_list):
    q_object = reduce(or_, (Q(name__icontains=merchant) for merchant in merchant_list))
    return Companies.objects.filter(q_object)

This would create a list of Q objects querying the name to contain a single element in merchant list. This would happpen for all the elements in merchant_list and all these Q objects would be reduced to a single Q object having mutliple ORs which can be directly applied to the filter query.

Answer 3

This is the approach that I adopted:

class MyManager(models.Manager):
    def exclusive_in(self, lookup, value_list):
        return self.filter(reduce(or_, (Q(**{lookup:_}) for _ in value_list)))

Here is now to use it:

Companies.objects.exclusive_in('name__icontains', possible_merchants])

It was inspired by other answers in this thread, as well as Django filter queryset __in for *every* item in list .

Answer 4

Another approach would be to simulate the actions that Django normally does for iexact queries (it converts both parts of the comparison statement to the upper case via SQL Upper function.

This way, the query will look like this:

Companies.objects.annotate(
    upper_name=models.Upper("name")
).filter(
    upper_name__in=[rchant.upper() for merchant in possible_merchants]
)