Query attached documents using C # MongoDB
I have a document called Record
that contains Athlete
as a subdocument. The structure looks like this in JSON:
{
"Id": "000000000000000000000000",
"Description": "sample string 1",
"Athlete": {
"Id": "123456789101112131415161",
"Name": "sample string 2",
"Username": "sample string 3",
...
},
...
}
How do you query this structure to retrieve an object Record
based on Athlete.Id
? I.E. If I have an Athlete ID and want to get their record, how do you do it?
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Method 1 : using raw BsonDocument: (it will return a list BsonDocument
)
var queryString = Query.EQ("Athlete.Id", "123456789101112131415161");
var resultBsons = collection.Find(queryString).ToList();
Way 2 . Another way is to use the typed version of the mongodb C # driver:
define 2 classes:
public class Athlete
{
public string Id { get; set; }
public string Name { get; set; }
public string Username { get; set; }
}
public class Record
{
public string Id { get; set; }
public string Description { get; set; }
public Athlete Athlete { get; set; }
}
then make your request
var url = new MongoUrl("mongodb://localhost");
var client = new MongoClient(url);
var server = client.GetServer();
var database = server.GetDatabase("test");
var collection = database.GetCollection<Record>("records");
var query = Query<Record>.EQ(i => i.Athlete.Id, "123456789101112131415161");
var result = collection.Find(query).ToList();
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You can request a sub-document field, using exactly the format that you specify: Athlete.Id
.
db.collection_name.findOne({"Athlete.Id": "123456789101112131415161"})
EDIT: To do this in C #, you can do something like this, assuming you have defined your Record document structure in a class named Record
:
IMongoQuery query = Query.EQ("Athlete.Id", "123456789101112131415161");
Record result = collection_name.FindOne(query);
Or if multiple documents can be returned using an appropriate identifier:
IMongoQuery query = Query.EQ("Athlete.Id", "123456789101112131415161");
MongoCursor<Record> resultCursor = collection_name.FindOne(query);
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