I have List<User> with this dependencies:
class User
{
public string Id { get; set; }
public List<ManagerGroup> ManagerGroups { get; set; }
}
class ManagerGroup
{
public string RoleId { get; set; }
public Manager[] Managers { get; set; }
}
class Manager
{
public string Id { get; set; }
}
and want to get the Dictionary value, where key is unique Manager.Id, and value is an array of Users who have this manager. It would be very grateful if you could add sorting by certain ManagerGroup.RoleIds.
Fiddle for tests
2
This should do what you want:
var users = new List<User>();
var usersByManagers = users
.SelectMany(u =>
u.ManagerGroups
.SelectMany(mg => mg.Managers
.Select(m => (ManagerId: m.Id, User: u)
)
)
)
.GroupBy(mu => mu.ManagerId)
.ToDictionary(g => g.Key, g => g.Distinct().Select(v => v.User).ToArray());
We flatten out the user/manager group/manager arrays into an enumerable of ManagerId/User, group by the manager id, and then build a dictionary with a distinct list of users.
Documentation:
SelectManySelectGroupByToDictionary
Demo (Credit to Yong Shun for the GenerateUsers method).
4
-
Get all managers and distinct.
-
Iterate from
managers, and filter the element from theuserslist which contains the manager’s Id in the nestedManagerslist.
var managers = users.SelectMany(x => x.ManagerGroups)
.SelectMany(x => x.Managers)
.DistinctBy(x => x.Id)
.ToList();
var managerAndAssociatedUsers = managers.ToDictionary(
k => k.Id,
v => users
.Where(x => x.ManagerGroups.Any(mg => mg.Managers.Any(m => m.Id == v.Id)))
// .Select(x => x.Id) // To only return User Id
.ToArray());
1