如何停止pg_search返回Rails中的所有列

Question

I have a pg_search_scope in a class called Name as follows:

pg_search_scope :fuzzy_search, 
                :against => [:surname, :forename, :other_names],
                :using => {
                   dmetaphone: {
                      tsvector_column: 'dmetaphone_search_vector'
                   },
                tsearch: {
                   dictionary: 'english',
                   tsvector_column: 'dictionary_search_vector'
                   }
                },
                :ranked_by => ":trigram"

I need to run a SELECT against the scope and just get back selective columns. I excepted the following todo that:

Name.select(:surname).fuzzy_search('smith')

but that generates:

SELECT surname, \"names\".*, ((similarity((coalesce(\"names\".\"surname\"::text, '') || ' ' || coalesce(\"names\".\"forename\"::text, '') || ' ' || coalesce(\"names\".\"other_names\"::text, '')), 'smith'))) AS pg_search_rank FROM \"names\"  WHERE (((\"names\".\"dmetaphone_search_vector\") @@ (to_tsquery('simple', ''' ' || pg_search_dmetaphone('smith') || ' '''))) OR ((\"names\".\"dictionary_search_vector\") @@ (to_tsquery('english', ''' ' || 'smith' || ' ''')))) ORDER BY pg_search_rank DESC, \"names\".\"id\" ASC

So as we can see that leaves \\"names\\".* in the query, which ofcourse returns all the columns.

Anyone else come across this? Any suggestions?

:)

Answer 1

Can the select statement come after the fuzzy_search call:

Name.fuzzy_search('smith').select(:surname)

If that doesn't work, try pluck :

Name.fuzzy_search('smith').pluck(:surname)

Answer 2

I was just running into this same issue over and over before finally figuring out a fix:

Name.fuzzy_search('smith').map(&:surname)

It's not ideal, because (as I understand it) it's technically loading all the fields before stripping away everything except :surname . But better than nothing, I suppose.