Upserting in Mongo DB using official C# driver

Question

In the official documentation of mongodb they mention upserts, so it would be really nice to write an upsert command instead of:

if (_campaignRepo.Exists(camp))
{
    _campaignRepo.DeleteByIdAndSystemId(camp);
}

_campaignRepo.Save(camp);

something which would implement that logic on the db level if it is possible. So what is the way to do an upsert if there is one?

Answer 1

The following code is from a working app:

weekplanStore.Update(
    Query.EQ("weekNumber", week),
    Update.Replace(rawWeekPlan),
    UpdateFlags.Upsert);

The weekplanStore is my MongoDB collection, and the code will update the document found with the query in the first argument or insert a new one if none is found. The "trick" is to use the UpdateFlags.Upsert modifier.

The rawWeekPlan is the object inserted or updated, and has the following type:

private class RawWeekPlan
{
    public ObjectId id;
    public int weekNumber;
    public WeekPlanEntry[] entries;
}

and turned into bson by the driver automatically.