Question

这些是我的实体;

class User
{
    [BsonId]
    public string Id { get; set; }
    public string name { get; set; }
    public List<Address> Adress { get; set; }
}

class Address
{
    [BsonId]
    public string Id { get; set; }
    public string AddressName { get; set; }
    public string AddressDetail { get; set; }

}

我的插入代码到mongo db如下，没有问题。

        const string uri = "mongodb://usermehmet:inno12345@localhost/testDB";
        var client = new MongoClient(uri);
        var db = client.GetServer().GetDatabase(new MongoUrl(uri).DatabaseName);

        counter++;

        User user=new User();
        user.Id = ObjectId.GenerateNewId().ToString();
        user.name = counter+"user";
        user.Adress = new List<Address>();

        Address a1=new Address();
        a1.Id = ObjectId.GenerateNewId().ToString();
        a1.AddressName = "Ev";
        a1.AddressDetail = "a sokak b caddesi c no d kat";

        Address a2=new Address();
        a2.Id = ObjectId.GenerateNewId().ToString();
        a2.AddressName = "İş";
        a2.AddressDetail = "x sokak y caddesi z no f kat";

        user.Adress.Add(a1);
        user.Adress.Add(a2);

        var collection2 = db.GetCollection<User>("Users");
        collection2.Insert(user);

但我从mongodb网站（Query an Array for an Element¶）获取的查询操作是在var result = collection.Find(filter).ToList();行创建编辑器错误。

 const string uri = "mongodb://usermehmet:inno12345@localhost/testDB";

        var client = new MongoClient(uri);
        var db = client.GetServer().GetDatabase(new MongoUrl(uri).DatabaseName);


        var collection = db.GetCollection<User>("Users");

        var filter = Builders<User>.Filter.Eq("name", "100user");
        var result = collection.Find(filter).ToList();

错误：

无法从MongoDB.Driver.FilterDefinition ConsoleApplication14.User转换为MongoDB.Driver.IMongoQuery

Answer 1

从GetServer()调用中可以看出，您可能正在使用较早版本的MongoDB .NET驱动程序。在旧API中，Find()函数需要IMongoQuery过滤器定义。

尝试更新MongoDB.Driver NuGet。如果我没弄错的话，最新的是v2.5。

Answer 2

我通过mongo db new api方法解决了问题，问题是GetServer，因为它已经过时了。

MongoClientSettings settings = MongoClientSettings.FromUrl(new MongoUrl("mongodb://usermehmet:inno12345@localhost/testDB"));
        var mongoClient = new MongoClient(settings);
        _database = mongoClient.GetDatabase("testDB");

        var collection=_database.GetCollection<User>("Users");
        var result = collection.Find(x=>x.name=="100user").ToList();

C＃Mongo DB collection.find（）方法不接受过滤器

2 个答案: