Blakes Seven questions

Blakes Seven answers

• Check if mongo document field exists
• MongoDb: How to aggregate, group and sort on date field?
• How to use a document property for $maxDistance in a $nearSphere query?
• Geonear sort by distance and time
• Upsert Document and/or add a Sub-Document
• Mongoose/mongodb - get only latest records per id
• Match all of the values specified in an array in Mongoose
• mongodb find with opposite of $elemMatch
• Match documents with fields not containing values in array
• Remove Duplicates from MongoDB