[英]Reading field's value in MongoDB with C#
I have Mongo DataBase.我有 Mongo 数据库。 I need to output field's values in my collection, but I can output only document.
我需要 output 字段的值在我的集合中,但我只能 output 文档。 I need to output doc.Name, doc.Email and doc.Password.
我需要 output doc.Name、doc.Email 和 doc.Password。 Thank you!
谢谢!
class Program
{
static void Main(string[] args)
{
var dbClient = new MongoClient("mongodb://127.0.0.1:27017");
IMongoDatabase db = dbClient.GetDatabase("Authentication");
string[] testlit;
var cars = db.GetCollection<BsonDocument>("Accounts");
var documents = cars.Find(new BsonDocument()).ToList();
foreach (BsonDocument doc in documents)
{
Console.WriteLine(doc.ToString());
}
Console.ReadLine();
}
}
You may do it like你可以这样做
var dbClient = new MongoClient("mongodb://127.0.0.1:27017");
IMongoDatabase db = dbClient.GetDatabase("Authentication");
var accounts = db.GetCollection<BsonDocument>("Accounts");
//accounts.InsertOne(new BsonDocument(new Dictionary<string, object>
//{
// ["Name"] = "Name of account", ["Email"] = "myemail@account.com",
// ["Password"] = "don't ever do that to me. I hope this is a hash...",
// ["SomeOtherField"] = "don't need it"
//}));
var projection = Builders<BsonDocument>.Projection.Include("Name").Include("Email").Include("Password").Exclude("_id");
var documents = accounts.Find(new BsonDocument()).Project(projection).ToList();
foreach (BsonDocument doc in documents)
{
Console.WriteLine($"Name: {doc.GetValue("Name")}\nEmail: {doc.GetValue("Email")}\nPassword: {doc.GetValue("Password")}");
//Name: Name of account
//Email: myemail @account.com
//Password: don't ever do that to me. I hope this is a hash...
}
With projection the fields are included/excluded at database.通过投影,字段在数据库中包含/排除。 Less data travels.
更少的数据传输。 If you need the values later, leave out the
projection
part.如果您稍后需要这些值,请忽略
projection
部分。 You can have your fields with doc.GetValue
.您可以使用
doc.GetValue
拥有您的字段。
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