Question

Im与MongoDB官方司机(10人)合作。我不能质疑莫奥果非行。我有以下班子:

public class UserData
{
    private ObjectId id;
    public ObjectId _id
    {
        get { return id; }
        set { id = value; }
    }       
    [BsonElement("Mail")]
    public string Email { get; set; }
    public string Name{ get; set; }
}

public class UserSettings
{
    private ObjectId id;
    public ObjectId _id
    {
        get { return id; }
        set { id = value; }
    }       
    [BsonElement("usr")]
    public MongoDBRef User { get; set; }
    public List<SettingsUser> Settings{ get; set; }
}

I want to make a query that having the UserData I fetch the UserSettings of that user. I try the following but it does not work:

var colletion = db.GetCollection<UserSettings>("UsrSettings"); 
collection.Find(Query.EQ("usr", usr._id);

我也试图这样做:

collection.Find(Query.EQ("usr", new MongoDBRef("UsrSettings", usr._id));

但由于MongoDBRef不是BsonValue,它没有汇编。

另一项尝试:

collection.FindOne(Query.EQ("usr.$id", User._id));

我例外: 未预见的元件。

任何想法? 还是工作? 感谢!

Answer 1

Sridhar回答了我在此提出的问题:https://groups.google.com/forum/#!msg/mongodb-user/Tip9A Qa_1TE/YAgflwJa3tAJ

The following should give you what you want (note I am using the 1.1 driver)

var refDocument = new BsonDocument { 
            {"$ref", "userdata"}, 
            {"$id", usr._id} 
        }; 
var query = Query.EQ("usr", refDocument); 
var result = userDataCollection.FindOne(query);

Here userdata is the name of the collection that stores user data. Having said that if all documents in the UserSettings collection always refer to only documents from the UserData collection then you should just use a manual reference as specified in http://www.mongodb.org/display/DOCS/Database+References#DatabaseReferences-DBRef. DBRefs are useful for the scenario where documents in a single collection can reference documents from multiple other collections.

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