public static void AddEmployee(Employee employee)
        {
            using (var conn = new SqlConnection(connStr))
            {
                const string commandStr = @"
                   INSERT INTO [dbo].[Сотрудники]
                           ([Фамилия]
                           ,[Имя]
                           ,[Отчество]
                           ,[Должность]
                           ,[Дата_рождения]
                           ,[Дата_приема_на_работу]
                           ,[Код_отдела]   )
                   VALUES (@lastName, @name, @patronymic, @position, @birthday, @dayOfEmployment, @kodOtd)";

                DbCommand command = conn.CreateCommand();
                command.CommandText = commandStr;
                command.CommandType = CommandType.Text;
                command.Parameters.Add(new SqlParameter
                {
                    ParameterName = "@lastName",
                    SqlDbType = SqlDbType.NVarChar,
                    Size = 50,
                    Value = employee.LastName
                });
                command.Parameters.Add(new SqlParameter
                {
                    ParameterName = "@name",
                    SqlDbType = SqlDbType.NVarChar,
                    Size = 20,
                    Value = employee.Name
                });
                command.Parameters.Add(new SqlParameter
                {
                    ParameterName = "@patronymic",
                    SqlDbType = SqlDbType.NVarChar,
                    Size = 50,
                    Value = employee.Patronymik
                });
                command.Parameters.Add(new SqlParameter
                {
                    ParameterName = "@position",
                    SqlDbType = SqlDbType.NVarChar,
                    Size = 50,
                    Value = employee.Position
                });

                command.Parameters.Add(new SqlParameter
                {
                    ParameterName = "@birthday",
                    SqlDbType = SqlDbType.Date,
                    Value = employee.Brthday
                });

                command.Parameters.Add(new SqlParameter
                {
                    ParameterName = "@dayOfEmployment",
                    SqlDbType = SqlDbType.Date,
                    Value = employee.DayOfEmployment
                });
                command.Parameters.Add(new SqlParameter
                {
                    ParameterName = "@kodOtd",
                    SqlDbType = SqlDbType.Int,
                    Value = employee.KodOtdela
                });


                conn.Open();

                command.ExecuteNonQuery();
            }
        }