CODEWITHSUNDEEP
c#mongodbmongodb-.net-driver
Benjamin E.
Benjamin E.

Reputation: 5162

Delete subdocument from array

Given below data, I want to delete all sub-documents in "data" where "k" == "c". That's my code:

var query = Query.EQ("templateId", "537c6648d7d6bd0a68a34918");
var update = Update.Pull("data", new BsonDocument() { { "k", "c" } });
MyMongoCollection.Update(query, update);

So what happens is that exactly 1 document is affected and the updating stops. I verified the query and it returns all documents as expected. Just with the pull-update, it breaks.

What could be wrong?

WriteConcern has no error. The query alone returns 3 docs and the WriteConcern has 1 doc affected.

{
    "_id" : ObjectId("537c85a2d7d6bd0a68a3491b"),
    "templateId" : "537c6648d7d6bd0a68a34918",
    "data" : [ 
        {"k" : "b", "v" : "111"}, 
        {"k" : "a", "v" : "222"}, 
        {"k" : "c", "v" : "333"}
    ]
},
{
    "_id" : ObjectId("537d6a41d7d6bd0608cb27a4"),
    "templateId" : "537c6648d7d6bd0a68a34918",
    "data" : [ 
        {"k" : "b", "v" : "111"}, 
        {"k" : "a", "v" : "222"}, 
        {"k" : "c", "v" : "333"}
    ]
}

Upvotes: 1

Views: 609

Answers (1)

Christian P
Christian P

Reputation: 12240

For updating multiple documents you should set the update flags to Multi:

MyMongoCollection.Update(query, update, UpdateFlags.Multi);

This will remove subdocuments from all documents.

From the MongoDB documentation:

By default, the update() method updates a single document that matches its selection criteria. Call the method with the multi option set to true to update multiple documents.

Upvotes: 1

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