How can I delete nested array element in a mongodb document with the c# driver

Question

I am new in the Mongodb world and now I am struggling of how can I delete, update element in a nested array field of a document. Here is my samle document:

{
    "_id" : ObjectId("55f354533dd61e5004ca5208"),
    "Name" : "Hand made products for real!",
    "Description" : "Products all made by hand",
    "Products" : [ 
        {
            "Identifier" : "170220151653",
            "Price" : 20.5,
            "Name" : "Leather bracelet",
            "Description" : "The bracelet was made by hand",
            "ImageUrl" : "https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQii6JCvXtx0iJGWgpvSl-KrdZONKYzDwS0U8uDvUunjO6BO9Aj"
        }
    ]
} 

In my method I get the id of the document and the id(Identifier) of the Product that I want to delete. Can anyone tell me how can I delete from the Products field the element having Identifier: 170220151653 ?

I tried:

var query = Query.And(Query.EQ("_id", categoryId), Query.EQ("Products.Identifier", productId));

            var update = Update.Pull("Products", new BsonDocument(){{ "Identifier", productId }});

            myDb.Applications().Update(query, update);

as suggested here: MongoDB remove a subdocument document from a subdocument

But I get an error at

myDb.Applications()

It just cant be found.

SOLVED:

var pull                = Update<Category>.Pull(x => x.Products, builder => builder.EQ(q => q.Identifier, productId));
            collection.Update(Query.And(Query.EQ("_id", ObjectId.Parse(categoryId)), Query.EQ("Products.Identifier", productId)), pull);

Answer 1

You are calling method Pull(string name, MongoDB.Bson.BsonValue value) and according to the docs it

Removes all values from the named array element that are equal to some value (see $pull)

and you provide { "Identifier", productId } as the value. I guess that mongo does not find that exact value.

Try to use the second overload of Pull with query-condition instead of exact value

Removes all values from the named array element that match some query (see $pull).

var update = Update.Pull("Products", Query.EQ("Identifier", productId));

UPDATE

Since you mention Category entity so I can suggest using lambda instead of Query.EQ:

var pull = Update<Category>.Pull(x => x.Products, builder =>
builder.Where(q => q.Identifier == productId));

Answer 2

I was also facing the same problem and then finally after doing lot of R&D, I came to know that, you have to use PullFilter instead of Pull when you want to delete using filter.

Answer 3

Hi as per my understanding you want to remove whole matched elements of given id and identifier so below query will may solve your problem but I don't know how to convert this into C#, here mongo $pull method use.

    db.collectionName.update({"_id" :  
        ObjectId("55f354533dd61e5004ca5208")},
        {"$pull":{"Products":{"Identifier":"170220151653"}}})