MongoDB: can't convert from BSON type EOO to Date
aggregation-framework, database, mongodb, nosql, ruby
Solution
The problem was that I was saving some documents without the timestamp field.
Problem
I' trying to use aggregation framework (with ruby) and project the date like this: ``` db['requests'].aggregate([ {"$project" => { _id: 0, method: '$method', user: '$user', year: {'$year' => '$timestamp'} }}]) ``` the document is like this one: ``` { _id: ObjectId("5177d7d7df26358289da7dfd"), timestamp: ISODate("2013-04-12T03:58:05+00:00"), method: "POST", status: "200", inputsize: "874", outputsize: "4981", user: "131" } ``` but i get the following error: ``` Mongo::OperationFailure: Database command 'aggregate' failed: (errmsg: 'exception: can't convert from BSON type EOO to Date'; code: '16006'; ok: '0.0'). ``` This is strange because it works correctly if I run this on the exactly same db which is imported with mongorestore.