Django Haystack - Filter by substring of a field using SearchQuerySet ()

Question

I have a Django project that uses SOLR for indexing.

I\'m trying to do a substring search using Haystack\'s SearchQuerySet

Answer 1

It's a bug in haystack.

As you said, __exact is implemented exactly like __contains and therefore this functionality does not exists out of the box in haystack.

The fix is awaiting merge here: https://github.com/django-haystack/django-haystack/issues/1041

You can bridge the waiting time for a fixed release like this:

from haystack.inputs import BaseInput, Clean


class CustomContain(BaseInput):
    """
    An input type for making wildcard matches.
    """
    input_type_name = 'custom_contain'

    def prepare(self, query_obj):
        query_string = super(CustomContain, self).prepare(query_obj)
        query_string = query_obj.clean(query_string)

        exact_bits = [Clean(bit).prepare(query_obj) for bit in query_string.split(' ') if bit]
        query_string = u' '.join(exact_bits)

        return u'*{}*'.format(query_string)

# Usage:
SearchQuerySet().filter(content=CustomContain('searchcontentgoeshere'))

Answer 2

That could be done using EdgeNgramField field:

some_field = indexes.EdgeNgramField() # also prepare value for this field or use model_attr

Then for partial match:

SearchQuerySet().all().filter(some_field='ear')