CoyoteMoves.Data_Access.EmployeeDB.GetNumberOfEmployeesInEachGroup C# (CSharp) Method

        public Dictionary<string, int> GetNumberOfEmployeesInEachGroup()
        {
            Dictionary<string, int> result = new Dictionary<string, int>();
            SqlConnection connection = new SqlConnection(_connectionString);
            SqlCommand command = new SqlCommand("SELECT IE.EmployeeID, G.Code FROM Intern_CoyoteMoves.dbo.InternalEmployee as IE LEFT JOIN Intern_CoyoteMoves.dbo.GroupType as G on G.GroupTypeID=IE.[Group]");
            command.Connection = connection;
            connection.Open();
            SqlDataReader reader = command.ExecuteReader();

            while (reader.Read())
            {
                if (reader["Code"] != System.DBNull.Value)
                {
                    if (result.ContainsKey((string)reader["Code"]) == false)
                    {
                        result[((string)reader["Code"])] = 1;
                    }
                    else
                    {
                        result[((string)reader["Code"])]++;
                    }
                }
                else
                {
                    if (result.ContainsKey("NULL"))
                    {
                        result["NULL"]++;
                    }
                    else
                    {
                        result["NULL"] = 1;
                    }
                }
            }
            return result;
        }