[Fixed]-Getting all the tags associated with the parent object using django-taggit

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I don’t think its possible in a single query but this solution will take five database queries:

# 1 query: Get restaurant
restaurant = Restaurant.objects.get(pk=pk)

# 2 query: Get content type of restaurant model
restaurant_ct = ContentType.objects.get_for_model(restaurant)

# 3 query: Get all reviews ids for a restaurant
reviews_ids = Review.objects.filter(content_type__id=restaurant_ct.id, object_id=restaurant.id).values_list('id', flat=True)

# 4 query: Get content type of review model
review_ct = ContentType.objects.get(app_label='review', model='review')

# 5 query: Get all tags
tags = TaggedItem.objects.filter(object_id__in=reviews_ids, content_type__id=review_ct.id)

But do note that the __in lookup on review ids might become costly on TaggedItem. But you wanted minimum database queries.

You can reduce one more query by fetching both content types of restaurant and review model in a single query but its not an elegant way:

ctypes = ContentType.objects.filter(
    app_label__in=['review', 'restaurant'],
    model__in=['review', 'restaurant']
)
assert len(ctypes) is 2
if ctypes[0].model == 'restaurant':
    restaurant_ct = ctypes[0]
    review_ct = ctypes[1]
else:
    review_ct = ctypes[0]
    restaurant_ct = ctypes[1]
👤Aamir Rind

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