Using unaccent with SearchVector and SearchQuery in Django

Question

I have installed UnaccentExtension in Django but I'm having problems using it with this search:

vector = SearchVector('title__unaccent', 'abstract__unaccent')
query = SearchQuery(word) | SearchQuery(word2)
files = Doc.objects.annotate(rank=SearchRank(vector, query)).order_by('-rank')

This is the error:

Cannot resolve keyword 'unaccent' into field. Join on 'title' not permitted.

Whit a simplest search it works fine:

Doc.objects.filter(title__unaccent=word)

So, what am I doing wrong?

Answer 1

You can't use 'unaccent' in 'SearchVector' but you have to define a new "unaccented" config in PostgreSQL.

1. If you missed, installs the unaccent extension.

2. Create your unaccented dictionary in PostgrSQL or using an empty migrations with this SQL:

   CREATE TEXT SEARCH CONFIGURATION french_unaccent( COPY = french );
   ALTER TEXT SEARCH CONFIGURATION french_unaccent
   ALTER MAPPING FOR hword, hword_part, word
   WITH unaccent, french_stem;
   

3. Use this configuration in your Django query :

   SearchVector('title','abstract', config='french_unaccent')
   SearchQuery(word, config='french_unaccent')
   

You can find more info about this type of configuration in the official PostgreSQL documentation on in various articles