Check out example codes for "c# distinct dictionary". It will help you in understanding the concepts better.

Code Example 1

var temp = _context.PlayerStats.Where(T => T.allianceId == _surf).Select(T => T.guildId).Distinct();
                var result = new Dictionary<string, string>();
                foreach (var item in temp)               
                    result[item] = _context.PlayerStats.FirstOrDefault(T => T.guildId == item).guildName;               
                return View(result);

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