Upsert

• A hybrid of update and insert operation.

• Syntax

  db.collection_name.update({<restriction query>}, {<update query>}, {"upsert": true})

• As shown in the above query syntax, upsert option enables us to do upsert operation, by default this option is false.

      db.iot.updateOne(
          { 
              "sensor": r.sensor, "date": r.date, 
              "valcount": { "$lt": 48 } 
          },
          { 
              "$push": 
                  { "readings": 
                      { "v": r.value, "t": r.time } 
                  },
                  "$inc": 
                      { "valcount": 1, "total": r.value } 
          },
          { "upsert": true }
      )