Question

我使用以下代码成功插入了一个文档：

 public async Task<List<Book>> ListBooks(BooksSearchFilter booksSearchFilter)
        {

    _client = new MongoClient(); //ConfigurationManager.AppSettings["MongoConnection"]
    _db = _client.GetDatabase(ConfigurationManager.AppSettings["MongoDatabaseName"]);

    var collection = _db.GetCollection<Book>("book");

    Publisher p = new Publisher { 
        Name = "O'Reilly Media", 
        Founded = 1980, 
        Location = "CA" };
    Book bookTest = new Book { 
        Language = "English", 
        Pages = 68, 
        PublishedDate = DateTime.Now, 
        Publisher = p, 
        Title = "MongoDB: The Definitive Guide" };
    bookTest.Author = new List<string>();
    bookTest.Author.Add("auth1");
    await collection.InsertOneAsync(bookTest);

    var books = await collection.Find(b => b.Language =="English").ToListAsync();
}

但是当我尝试使用以下代码读取记录时，它返回一个空列表：

var books = await collection.Find(b => b.Language == "English").ToListAsync();

请注意，当我按F10在调试器中跳过此行时，光标消失，Fiddler显示空结果，我是否会遗漏某些内容？

我使用的实体：

public class Book
{
    [BsonId]
    [BsonRepresentation(BsonType.ObjectId)]
    public string  Id { get; set; }

    //[BsonElement("title")]
    public string Title { get; set; }

    //[BsonElement("author")]
    public List<string> Author { get; set; }

    //[BsonElement("published_date")]
    public DateTime PublishedDate { get; set; }

    //[BsonElement("pages")]
    public double Pages { get; set; }

    //[BsonElement("language")]
    public string Language { get; set; }

    //[BsonElement("publisher")]
    public Publisher Publisher { get; set; }

}

public class Publisher
{
    //[BsonElement("name")]
    public string Name { get; set; }

    //[BsonElement("founded")]
    public double Founded { get; set; }

    //[BsonElement("location")]
    public string Location { get; set; }
}

Answer 1

我试图重现你所描述的内容，但是当我使用F10来跨过这行代码时：

var books = await collection.Find(b => b.Language == "English").ToListAsync();

结果是books变量的值是一个List，其中包含一个元素，正如预期的那样。

Fiddler无论如何都不会显示任何内容，因为它监视HTTP流量，MongoDB驱动程序和服务器之间的协议是TCP套接字上的二进制协议。

MongoDB使用嵌入式文档读取文档 - c＃

1 个答案: