Question

I have many collections of documents in a mongo database that look like this:

{
   "_id": ObjectId("4ee5e9079b14f74ef14ddd2f"),
   "number": 456,
   "date": "2012-02-13"
}

I need to rename the field "created_at" to "date" and I’m using Rockmongo. I think the best way to go about renaming this field would be to use the execute panel in Rockmongo. Basing my code off of this post I tried this:

function rename(x){
   db_name.coll_name.update({"_id":x._id}, {
      $rename: {"date":"created_at"}
   });
}

db_name.coll_name.find({"date":{$ne:null}}).forEach(rename);

but have been unsuccessful. I have mainly worked with pymongo (and could do it with that), but I think learning this execute panel would be very helpful as I continue to use rockmongo.

Answer 1

If you want to do all of the documents in your collection, you can do it all at once with a multi update, like so:

db.coll_name.update({},{$rename:{"created_at":"date"}},false,true);

Where “false” is the upsert option, and “true” is the multi-update option.

Hope that helps.

Updated with an example. It even works if the field is already partly renamed, or if the field doesn’t exist in all documents:

> db.test2.insert({x:12});
> db.test2.insert({x:12});
> db.test2.insert({x:12});
> db.test2.insert({});
> db.test2.update({},{$rename:{"x":"x2"}},false,true);
> db.test2.find();
{ "_id" : ObjectId("4f68afb1206dcc69f52c2157"), "x2" : 12 }
{ "_id" : ObjectId("4f68afb2206dcc69f52c2158"), "x2" : 12 }
{ "_id" : ObjectId("4f68afb2206dcc69f52c2159"), "x2" : 12 }
{ "_id" : ObjectId("4f68afb5206dcc69f52c215a") }