se koden nedenfor. den bruger mit bibliotek MongoDB.Entities som har indbygget understøttelse af en-til-en, en-til-mange og mange-til-mange relationer mellem enheder.
using MongoDB.Entities;
using System.Linq;
namespace StackOverflow
{
public class Program
{
public class Account : Entity
{
public string Name { get; set; }
public Many<User> Users { get; set; }
public Account() => this.InitOneToMany(() => Users);
}
public class User : Entity
{
public string FirstName { get; set; }
public string LastName { get; set; }
public One<Account> Account { get; set; }
[Ignore]
public string AccountName { get; set; }
}
private static void Main(string[] args)
{
new DB("test");
var account = new Account { Name = "parent account" };
account.Save();
var user = new User
{
FirstName = "dave",
LastName = "mathews",
Account = account.ToReference()
};
user.Save();
account.Users.Add(user);
//find parent by ID
var parent = DB.Find<Account>().One(account.ID);
//get first user of parent
var dave = parent.Users.ChildrenQueryable()
.FirstOrDefault();
//get dave's account
var davesAccount = dave.Account.ToEntity();
//get dave with account name filled in by a single mongo query
var daveExtra = (from u in DB.Queryable<User>().Where(u => u.ID == dave.ID)
join a in DB.Queryable<Account>() on u.Account.ID equals a.ID
select new User
{
ID = u.ID,
FirstName = u.FirstName,
LastName = u.LastName,
AccountName = a.Name
}).SingleOrDefault();
}
}
}