Home/ Questions/Q 8304579
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-08T17:53:18+00:00

I’m writing a small torrent indexer in Ruby ( here ) and would love

  • 0

I’m writing a small torrent indexer in Ruby (here) and would love to support MongoDB as an option for the database. Currently, I have the database set up with a many-to-many relationship between tags and torrents.

How would I format a query that gets all the torrent_ids from a map table that match to all the tags in a given list?

I did this in SQL like this:

select torrent_id, count(*) num from tagmap where tag_id in (tag1, tag2, tag3, tag4) group by torrent_id having num = 4"

EDIT: I am right now working only with the collection with torrent_id and tag_id. That’s all it has in there. So I’m mapping ids to ids and naught more.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    It’s better to create a collection to create the mapping consisting tag_id’s and torrent_id’s. Whenever you add a torrent, also add the torrents tags to the torrenttags collection. Index should be on tag_id.

    You can use the following query syntax to get a list of torrents matching more than one tag.

    db.tagmap.find({tag_id:{$in: ['tag1','tag2','tag3','tag4']}});

    For Aggregation (group by, count) you need to use MapReduce

    • 0