How to set primary key with auto increment in MongoDB? [duplicate]

Answer 1

$db->execute("return db.getCollection('autoInccollection').findAndModify({
                        query: { collection: '$colle' },
                        update: { '$inc': { primaryKey: 1 } },new: true
                            })");

$colle means which collection you need to create the Auto increment key.

Answer 2

I blogged about this here:
http://www.alexjamesbrown.com/blog/development/mongodb-incremental-ids/

I also started a int id generator for the C# driver:
https://github.com/alexjamesbrown/MongDBIntIdGenerator

However, incrementing ID's won't scale effectively.