No array filter found for identifier '-1'-CodePudding

I am developing a .NET application with MongoDB, using C# driver 2.14. My query is as follows:

I have an embedded array elements, eg:

{
    "_id" : 1,
        "Friends" : [
                {
                        "_id" : 2,
                        "FirstName" : "Bob",
                        "LastName":"Marley",
                        "Gender":"Male",
                        ...
                },
                {
                        "_id" : 3,
                        "Name" : "Jonson",
                        "LastName":"Charles",
                        "Gender":"Male",
                        ...
                },
                {
                        "_id" : 4,
                        "Name" : "Bob",
                        "LastName":"",
                        "Gender":"Male",
                        ...
                }
        ]
}

which has multiple fields in it. I need to update all the values in one of the nested documents.

I have written a code as follows:

var filter1 = Builders<BsonDocument>.Filter.Eq("_id", 1);
var filter2 = Builders<BsonDocument>.Filter.ElemMatch<BsonValue>("Friends", new BsonDocument(){ {"_id", 2 }});

var update = Builders<BsonDocument>.Update.Set("Friends.$[-1]", BsonDocument.Parse(JsonConvert.SerializeObject(object)));

await collection.UpdateAsync(filter1&filter2, update);

I am getting the exception as:

No array filter found for identifier '-1'

Can anyone please suggest whether it's the right approach?

CodePudding user response：

It is an invalid syntax/statement in MongoDB for

"Friends.$[-1]"

You need