Re: Updating a specific mongodb value using the offical c# driver

[Andre de Frere]

Hi,

Not sure which ways you were trying to update using .update() and .add(), but .update() is one way to get your the outcome you are looking for.

You could use an update command directly:

var query = new QueryDocument {
    { "geolocationPresent", "Yes" }
};
var update = new UpdateDocument {
{ "$set", new BsonDocument("geolocationPresent", "Checked") }
};
collection.Update(query, update);

or by using a Query builder (available when using MongoDB.Driver.Builders)

var query = Query.EQ("geolocationPresent", "Yes");
var update = Update.Set("geolocationPresent", "Checked");
collection.update(query, update);

Both of the above snippets will set all of the documents with {geolocationPresent : "Yes"} to {geolocationPresent : "Checked"} without changing the values of other fields in those documents (or removing them).

Let me know if this helps,

André

[Andre de Frere]

Hi,

Apologies, I was intending to include in my answer a method of saving each document in turn (rather than the whole collection at the same time).

You could use something like the following to update each document in turn as you iterate through the collection:

foreach (BsonDocument item in collection.Find(query)) 
{ 
BsonElement geolocationPresent = item.GetElement("geolocationPresent"); 
geolocationPresent.Value = "Checked";
item.SetElement(geolocationPresent);
collection.Save(item);
}

Hopefully this is helpful to you,

André