无法使用pg_search gem从Postgres中摘录

Question

Update

First of all, there is no method "context". That was a word my brain made up at some point and stuck with. Obviously I should've been running .excerpt(). Second, I was running the command against the returned array, not an individual instance of the PG_Search::Document

Double mistakes, but yes the code does in fact work.

End Update

First some system info:

• Ruby 1.9.3p194
• Rails 3.2.13
• pg_search 0.5.7
• Postgres 9.2.3 (with unaccent enabled)

I'm trying to follow the progress made in this thread: ( How to show excerpts from pg-search multisearch results )

Okay so assuming the use of the following query cribbed from that post:

@query = params[:query]
PgSearch.multisearch(@query).select("ts_headline(pg_search_documents.content, plainto_tsquery('english', ''' ' || unaccent('#{@query}') || ' ''' || ':*')) AS excerpt")

returns:

=> [#<PgSearch::Document id: 7, content: "1 <p>You think water moves fast? You should see ice...", searchable_id: 2, searchable_type: "Release", created_at: "2013-03-27 18:58:52", updated_at: "2013-03-27 18:58:52">]

It successfully returns some search results but they don't have the context method at all. It's as if I just called multisearch without the select method.

I'm a newbie when it comes to SQL and Postgres so I'm not exactly sure where to start in debugging that snippet. I would love some help debugging or getting an explanation of what is happening.

Also, an aside that I think is important, I want to thank anyone who works on pg_search or responds to questions like these. You make the world a better place.

Answer 1

You have to select the other columns you need as well.

For example

sanitized = ActionController::Base.helpers.sanitize(params[:q])
@results = PgSearch.multisearch(params[:q])
                  .select(:id, :content, :searchable_id, :searchable_type)
                  .select(["ts_headline(pg_search_documents.content, plainto_tsquery('english', ''' ' || '#{sanitized}' || ' ''' || ':*')) AS excerpt"])

Will return the id, content, searchable_id, searchable_type, excerpt

Also notice the sanitizing. Don't want to suffer from an sql injection attack. :]