using System;

using System.Collections.Generic;

using System.Linq;

​

var users = new List<User>

{

    new(1, "Петя"),

    new(2, "Вася"),

    new(3, "Катя")

};

var works = new List<Work>

{

    new(1, 1, 2, 3)

};

​

var query =

    from work in works

    join user1 in users on work.User1 equals user1.UserID

    join user2 in users on work.User2 equals user2.UserID

    join user3 in users on work.User3 equals user3.UserID

    select new WorkView(work.WorkID, user1.Name, user2.Name, user3.Name);

​

Console.WriteLine(string.Join(Environment.NewLine, query));

​

sealed record User(int UserID, string Name);

sealed record Work(int WorkID, int User1, int User2, int User3);

sealed record WorkView(int WorkID, string User1, string User2, string User3);