Multikey indexing in rails mongoid

Question

I want to store data in this format.

{
 "_id": ObjectId(...)
 "title": "Grocery Quality"
 "comments": [
    { author_id: ObjectId(...)
      date: Date(...)
      text: "Please expand the cheddar selection." },
    { author_id: ObjectId(...)
      date: Date(...)
      text: "Please expand the mustard selection." },
    { author_id: ObjectId(...)
      date: Date(...)
      text: "Please expand the olive selection." }
 ]
}

I'm confused as to how to achieve this format for my data.

I am using mongoid; does Mongoid support Multikey Indexing?

How can use mongoid to achieve my desired format and behaviour?

@gami What is the question actual looking for I'm confuse how to create embed document or how to create multi-indexing Mongoid doesnot support multikey indexing it something MONGODB would do — Viren, Mar 01 '13 at 17:20
@Viran then how to configure such db collection with mongoid? — Ganesh Kunwar, Mar 02 '13 at 16:47
@Ganeshkunwar I thought the question was from Gami what is field u want to index on since the OP itself has not specified that detail and it viren — Viren, Mar 03 '13 at 14:24
@Viran, I have faced same problem and not getting solution yet. — Ganesh Kunwar, Mar 04 '13 at 02:01

score 1 · Answer 1 · answered Mar 22 '13 at 05:01

I'm not sure if I got your doubt correctly but as I can't comment I'm answering right away. If it isnt this what you asked, please explain a little bit more =)

You have your model with those fields you wrote before, I will call it Post model. For the comments on it, I would suggest you create another model callend Comment and embed it on the Post model:

class Post
  field: title
  embeds_many :comments
end

class Comment
  field :date
  field :text
  has_one :author
  embedded_in :post
end

And to index the comments on the Post model you could do:

index({ :"comments.updated_at" => 1 })

Multikey indexing in rails mongoid

1 Answers1