I have following collection.

{
        "_id" : ObjectId("51fa56408e843042c0c24e3d"),
        "uniqDates" : [
                ISODate("2013-07-30T18:30:00Z"),
                ISODate("2013-07-31T18:30:00Z")
        ]
}
{
        "_id" : ObjectId("51fa5648c424ea3e37199502"),
        "events" : [
                {
                        "eid" : 1,
                        "title" : "Event 1",
                        "start" : ISODate("2013-08-04T18:30:00Z")
                },
                {
                        "eid" : 2,
                        "title" : "Event 2",
                        "start" : ISODate("2013-08-08T18:30:00Z")
                }
        ]
}

I want to update a document in "events" array if it exists (i want to check it by eid), if it doesn't exists i want to insert that document.

currently i am doing this with two queries.

db.col.update({events: {$exists: 1}}, {$pull: {"events": {"eid": 2}}});

and

db.schedule.update({events: {$exists: 1}}, {$addToSet: 
{"events": {"eid": 2, "title": "Event 4", "start": new Date(2013, 08, 02)}}});

Is there a way to do this with single query? Something with upsert operation.

UPDATE: I suggest to read my accepted answer, which gives you different approach on this problem.

I have following collection.

{
        "_id" : ObjectId("51fa56408e843042c0c24e3d"),
        "uniqDates" : [
                ISODate("2013-07-30T18:30:00Z"),
                ISODate("2013-07-31T18:30:00Z")
        ]
}
{
        "_id" : ObjectId("51fa5648c424ea3e37199502"),
        "events" : [
                {
                        "eid" : 1,
                        "title" : "Event 1",
                        "start" : ISODate("2013-08-04T18:30:00Z")
                },
                {
                        "eid" : 2,
                        "title" : "Event 2",
                        "start" : ISODate("2013-08-08T18:30:00Z")
                }
        ]
}

I want to update a document in "events" array if it exists (i want to check it by eid), if it doesn't exists i want to insert that document.

currently i am doing this with two queries.

db.col.update({events: {$exists: 1}}, {$pull: {"events": {"eid": 2}}});

and

db.schedule.update({events: {$exists: 1}}, {$addToSet: 
{"events": {"eid": 2, "title": "Event 4", "start": new Date(2013, 08, 02)}}});

Is there a way to do this with single query? Something with upsert operation.