Restoring single objects in mongodb

Today I had the need to restore single objects from a mongodb installation. mongodb offers two tools for this mongodump and mongorestore, both of which seem to be designed to only dump and restore whole collections.

So I'll demonstrate the workflow just to restore a bunch of objects. Maybe it's a clumsy way, but we'll improve this over time.

So, we have an existing backup, done with mongodump (for example through a daily, over-night backup). This consists of several .bson files, one for each collection.

  1. Restore a whole collection to a new database: mongorestore -d newdb collection.bson
  2. Open this database: mongo newdb
  3. Find the items you want to restore through a query, for example: db.collection.find({"_id": {"$gte": ObjectId("4da4231c747359d16c370000")}});
  4. Back on the command line again, just dump these lines to a new bson file: mongodump -d newdb -c collection -q '{"_id": {"$gte": ObjectId("4da4231c747359d16c370000")}}'
  5. Now you can finally import just those objects into your existing collection: mongorestore -d realdb collection.bson