你要自己做东西?

public class MongoDbBase
{
　　public ObjectId _id { get; set; }
}

public class StoreBase<T> where T : MongoDbBase
{
　　protected readonly static IQueryable<T> LinqQuery;
　　protected readonly static MongoCollection<T> Collection;

static StoreBase()
{
　　var mongoUrl = new MongoUrl("mongodb://127.0.0.1:27017");
　　var clientSettings = MongoClientSettings.FromUrl(mongoUrl);
　　if (!clientSettings.WriteConcern.Enabled)
　　{
　　　　clientSettings.WriteConcern.W = 1; // ensure WriteConcern is enabled

　　　　regardless of what the URL says
　　}
　　string collectionName = typeof(T).Name;
　　var client = new MongoClient(clientSettings);
　　var server = client.GetServer();
　　var db = server.GetDatabase("WebApi");
　　Collection = db.GetCollection<T>(collectionName);
　　LinqQuery = Collection.AsQueryable();
}

/// <summary>
/// 获取所有元素
/// </summary>
public IEnumerable<T> GetAll()
{
　　return Collection.FindAll();
}

/// <summary>
/// 根据Id获取一个元素
/// </summary>
public T Get(ObjectId id)
{
　　return Collection.FindOneById(id);
}

/// <summary>
/// 插入一个元素
/// </summary>
public T Add(T item)
{
　　if (Collection.Insert(item).Ok)
　　{
　　　　return item;
　　}
　　throw new MongoException("往MongoDb插入失败");
}

/// <summary>
/// 根据ID删除元素
/// </summary>
public void Remove(ObjectId id)
{
　　Collection.Remove(Query.EQ("_id", id));
}

public long RemoveAll()
{
　　long rt=Collection.Count();
　　Collection.RemoveAll();
　　return rt;
}

/// <summary>
/// 局部更新
/// 当字段存在时更新字段,不存在时添加新字段
/// </summary>
public bool Update(ObjectId id, object pms)
{
　　return
　　Collection.Update(Query.EQ("_id", id),
　　new UpdateDocument { { "$set", new QueryDocument {pms.ToBsonDocument() } } }).Ok;
}

/// <summary>
/// 保存修改
/// 当ID不存在时创建新行,存在时更新旧数据
/// </summary>
public bool Save(T doc)
{
　　return Collection.Save(doc).Ok;
}