Text search not working with MongoDB 3.0.0

[glampr]

I get the following error when upgraded to MongoDB 3.0.0 :

Moped::Errors::OperationFailure: The operation: #<Moped::Protocol::Command
  @length=100
  @request_id=3
  @response_to=0
  @op_code=2004
  @flags=[]
  @full_collection_name="geonames.$cmd"
  @skip=0
  @limit=-1
  @selector={:text=>"cities1000", :search=>"athens", :filter=>{}}
  @fields=nil>
failed with error 59: "no such command: text"

This is the command I was using that was working in MongoDB 2.6

GeoName.mongo_session.command(
        text: collection,
        search: query,
        filter: filters,
        # project: { ... },
        limit: 10,
        # language: "english"
)

Tested against moped 2.0.4

[glampr]

http://docs.mongodb.org/manual/release-notes/3.0-compatibility/#removed-deprecated-commands

[arthurnn]

Didnt know that 3.0 didnt accept text search anymore.
In that case we will have to remove it from moped/mongoid, but thats only on future versions.
thanks for reporting

[glampr]

Currently this works: Model.where({"$text" => {"$search" => query}})
but the current Origin API does not allow to include the textScore, neither to sort by the textScore.
It would be good if when you tackle this in a new version, you could allow these.
I'm monkey patching the Original::Optional module to achieve this for now

module Origin
  module Optional
    def with_fields(fields_def = {})
      fields_def ||= {}
      fields_def.merge!({_id: 1})
      option(fields_def) do |options|
        options.store(:fields,
          fields_def.inject(options[:fields] || {}) do |sub, field_def|
            key, val = field_def
            sub.tap { sub[key] = val }
          end
        )
      end
    end

    def include_text_search_score
      with_fields({score: {"$meta" => "textScore"}})
    end

    def sort_by_text_search_score
      option({}) do |options, query|
        add_sort_option(options, :score, {"$meta" => "textScore"})
      end
    end
  end
end

and using it like this:

Model.where({"$text" => {"$search" => query}}).
          include_text_search_score.
          sort_by_text_search_score.
          only(:name, :alternate_names, :coordinates). # you have to manually specify the fields because of including the score field
          limit(10)

[krsyoung]

Thanks for sharing @glampr! Definitely helps ... seems like there is no official way of doing this.

[glampr]

When upgrading to mongoid >= 5 which doesn't use moped, you can use directly the ruby driver (>= 2.1) like this:

Model.collection.
  find({"$text" => {"$search" => query}}).
  projection(field1: 1, field2: 1, field3: 1, score: {"$meta" => "textScore"}).
  sort({score: {"$meta" => "textScore"}}).
  limit(some_limit).
  entries.
  map { |g| Model.new(g) } # optional if you want objects and not hashes

[krsyoung]

Beautiful, thanks @glampr 👍

[shahfaizanali]

Can anyone tell me how I can add text index in mongoid model?
I tried this
index({company_name: 1, first_name: 1, last_name: 1 })

Model.text_search 'something'
gives Mongo::Error::OperationFailure: text index required for $text query

[lalit-nga]

hi @glampr, I have used your suggestion. But I am getting below error.

Person.collection.find({"$text" => {"$search" =>"yogesh jain"}}).projection(email: 1).entries
Mongo::Error::OperationFailure: text index required for $text query (27)
	from (irb):8:in `entries'
	from (irb):8

I have also put the below code for above with no luck.

index({ first_name: 'text' })
index({ email: 'text' }, { unique: true, background: true })

How I reindex the existing data? Thanks :)

[glampr]

@lalit-nga just adding the index statements in your model does not add the text index to the database. you also need to run rake db:mongoid:create_indexes

[hartator]

Is @glampr answer still the best way to handle this?

Running with success:

def self.search query, limit=0
  Location.collection.
    find({"$text" => {"$search" => query}}).
    projection(score: {"$meta" => "textScore"}).
    sort({score: {"$meta" => "textScore"}}).
    limit(limit).
    entries.
    map { |e| Location.new(e) }
end

Just kind of wish I can chain search with regular Mongoid::Criteria, but that's a detail.

[hartator]

On a side note, beware of both mongoid_search and mongoid_fulltext gems as they seem to reimplement their own full text indexes that might be overkill in your use cases.