Question

I currently have a collection with documents like the following:

{ foo: 'bar', timeCreated: ISODate("2012-06-28T06:51:48.374Z") }

I would now like to add a timestampCreated key to the documents in this collection, to make querying by time easier.

I was able to add the new column with an update and $set operation, and set the timestamp value but I appears to be setting the current timestamp using this:

db.reports.update({}, { 
    $set : { 
        timestampCreated : new Timestamp(new Date('$.timeCreated'), 0) 
    } 
}, false, true);

I however have not been able to figure out a way to add this column and set it’s value to the timestamp of the existing ‘timeCreated’ field.

Answer 1

Do a find for all the documents, limiting to just the id and timeCreated fields. Then loop over that and generate the timestampCreated value, and do an update on each.