How do you implement an auto-incrementing primary ID in MongoDB?

Question

Just like in MYSQL, I want an incrementing ID.

Answer 1

@TIMEX : Check if below link can help you, if you were looking for a sequence number not ID (coz ID is reserved by mongo)

http://docs.mongodb.org/manual/tutorial/create-an-auto-incrementing-field/#auto-increment-counters-collection

@Dennis Burton Auto increment if user does will it not cause collision? i feel, hence mongo db uses its own _Id so it can avoid collision, but if user wishes to have a column as a running sequence they are free to have it