How can I update mongodb document for adding a new item to array?

Question

I couldn't figure out insert to a sub array...

• _id
• MyArray
• --Item
• ----ArrayItemId
• ----Name

I want to insert items to MyArray...

How my update document should be?

MyCollection.Update( 
 new QueryDocument { { "_id", MyObject.Id } },
 new UpdateDocument { { "$set", new BsonDocument { { "MyArray", 
       new BsonArray { new BsonDocument {{ "ArrayItemId", myArrayField.Id }},
                       new BsonDocument {{ "Name", myArrayField.Name }} }}}}}, 
 UpdateFlags.None);

Answer 1

Inserting in an array is done using the $push operator.

As a side note, you don't need to use QueryDocument and UpdateDocument. There's a much easier helper syntax:

MyCollection.Update(Query.EQ("_id", MyObject.Id), 
                    Update.PushWrapped("MyArray", myArrayField)

Note that PushWrapped<T> allows to push documents, while Push accepts only such types that can be represented by a simple field in MongoDB.