List of users with a list of roles in Identity 2.2.1

Question

So, I searched Google and SO. He feels that this question has been asked many times, but the answer did not help me, but I feel that I am getting closer. However, I am new to LINQ and Lambda, and I don't have the knowledge to do what I want.

Desired Result

User                   Roles
-----------------------------------------
John                   Admin
Jane                   Staff, HR, Payroll
MyCoolUserName         User

I am pretty close to this post and this post . Here is what I got so far.

ViewModel:

public class UsersViewModel {
    [Display(Name = "User")]
    public ApplicationUser User { get; set; }

    [Display(Name = "Roles")]
    public string Roles { get; set; }
}

Controller:

Trial No. 1

This solution returns spaces for roles, and I had to add this to my file web.config:<roleManager enabled="true" />

public class UsersController : Controller {
    public async Task Index() {
        var allUsers = await db.Users.ToListAsync();
        var users = new List();
        foreach (var user in allUsers) {
            String[] roles = Roles.GetRolesForUser(user.UserName);
            users.Add(new UsersViewModel {User = u, Roles = String.Join(",", roles.ToArray())});
        }
        return View(users);
    }
}

Trial No. 2

This solution returns one row for each user per role, but only returns RoleId

public class UsersController : Controller {
    public async Task Index() {
        var allUsers = await db.Users.ToListAsync();
        var users = allUsers.Select(u => new UsersViewModel {User = u, Roles = String.Join(",", u.Roles.Select(r => r.RoleId))}).ToList();
        return View(users);
    }
}

Here is what I get for Trial # 2 when I change RoleIdto RoleName:

, №2 u.Roles UserRoles. , , , Roles .

, - ? .

Answer 1

@Kienct89 , , . , - , .

: , , 1 , 2.

1

public class UsersController : Controller {
    public async Task Index() {
        var allUsers = await db.Users.ToListAsync();
        var users = allUsers.Select(u => new UsersViewModel {User = u, Roles = String.Join(",", db.Roles.Where(role => role.Users.Any(user => user.UserId == u.Id)).Select(r => r.Name))}).ToList();
        return View(users);
    }
}

2 (?)

public class UsersController : Controller {
    public async Task Index() {
        var allUsers = await db.Users.ToListAsync();

        // set all roles to a variable, so that we don't hit the database for every user iteration
        // is this true?
        var allRoles = await db.Roles.ToListAsync();

        var users = allUsers.Select(u => new UsersViewModel {User = u, Roles = String.Join(",", allRoles.Where(role => role.Users.Any(user => user.UserId == u.Id)).Select(r => r.Name))}).ToList();
        return View(users);
    }
}

, 2 , , . . , , , .

Answer 2

LINQ, UserRole - ( EF). , , - Lazy Loading, Include (entity), .

:

"Lazy Loading":

public class UsersController : Controller {
    public async Task Index() {
        var users = allUsers.Include(Roles).Select(u => new UserViewModel {UserName = u.UserName, Roles = String.Join(",", u.Roles.Select(r => r.RoleName))}).ToList();
        return View(users);
    }
}

"Lazy Loading":

public class UsersController : Controller {
    public async Task Index() {
        var users = allUsers.Select(u => new UserViewModel {UserName = u.UserName, Roles = String.Join(",", u.Roles.Select(r => r.RoleName))}).ToList();
        return View(users);
    }
}

UPDATE: , , 3 (Users, Roles, UserRoles), "--" ( gif, UserId RoleId).

public class UsersController : Controller {
    public async Task Index() {
        var users = allUsers.Select(u => new UserViewModel {UserName = u.UserName, Roles = String.Join(",", u.UserRoles.Where(userRole => u.Roles.Select(r => r.RoleId).Contains(userRole.Id)).Select(userRole => userRole.Name)}).ToList();
        return View(users);
    }
}