CodeIgniter return尝试获取非对象的属性

It is not a good practice to use like this. We cannot ensure that the query will always produce a result it depends on database table. if $this->db->get_where returns no results then it cannot invoke the row() method and access the field idso it will raise an error.

So always do like this

public function get_admin_role_id()
{
   $result = $this->db->get_where('ea_roles', array('slug' => DB_SLUG_ADMIN));
   if($result->num_rows()==0){
     echo "Result not found!";
   } 
   else{
    $row = $result->row();
    $id = intval($row->id);
  }
}

Please make sure that this query have some result.

select * from ea_roles where slug='your_slug'; 

Try the following:

public function get_admin_role_id() {
    return intval($this->db->get_where('ea_roles', array('slug' => DB_SLUG_ADMIN))->row()->id);
}

If this doesn't return anything then you don't have such record in the database

Be sure to have all of your database setted up correctly. execute the following SQL query within your phpmyadmin

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;

--
-- Database: `easyappointments`
--

--
-- Dumping data for table `ea_settings`
--

INSERT INTO `ea_settings` (`id`, `name`, `value`) VALUES
(1, 'company_working_plan', '{"monday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"tuesday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"wednesday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"thursday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"friday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"saturday":null,"sunday":null}'),
(2, 'book_advance_timeout', '30'),
(3, 'company_name', 'ABC Company'),
(4, 'company_email', 'info@abc-company.ea'),
(5, 'company_link', 'http://www.abc-company.ea'),
(6, 'google_analytics_code', '');

--
-- Dumping data for table `ea_roles`
--

INSERT INTO `ea_roles` (`id`, `name`, `slug`, `is_admin`, `appointments`, `customers`, `services`, `users`, `system_settings`, `user_settings`) VALUES
(1, 'Administrator', 'admin', 1, 15, 15, 15, 15, 15, 15),
(2, 'Provider', 'provider', 0, 15, 15, 0, 0, 0, 15),
(3, 'Customer', 'customer', 0, 0, 0, 0, 0, 0, 0),
(4, 'Secretary', 'secretary', 0, 15, 15, 0, 0, 0, 15);

--
-- Dumping data for table `ea_users`
--

INSERT INTO `ea_users` (`id`, `first_name`, `last_name`, `email`, `mobile_number`, `phone_number`, `address`, `city`, `state`, `zip_code`, `notes`, `id_roles`) VALUES
(1, 'John', 'Smith', 'info@abc-company.ea', '0123 4567890', '0123 4567891', 'Tst-Address 12', 'Tst-City', 'Tst-State', '012345', 'Test administrator record for this installation. ', 1),
(2, 'George ', 'Clayton', 'g.clayton@abc-company.ea', '0123 456 7890', '0123 456 7891', 'Tst-Address 12', 'Tst-City', 'Tst-State', '012345', 'This is one of the test providers. He will handle the quick services.', 2),
(3, 'Christina', 'Nickolson', 'c.nickolson@abc-company.ea', '0123 4567890', '0123 4567891', 'Tst-Address 12', 'Tst-City', 'Tst-State', '012345', 'This provider will handle the long services.', 2),
(4, 'Nicky', 'Rowland', 'n.rowland@abc-company.ea', '0123 4567890', '0123 4567891', 'Tst-Address 12', 'Tst-City', 'Tst-State', '012345', 'This is the only secretary of the app. She will handle the data of Christina.', 4),
(5, 'John', 'Doe', 'john.doe@abc-company.ea', NULL, '0123 4567890', 'Tst-Address 12', 'Tst-City', NULL, '012345', 'This is a test customer record.', 3);

--
-- Dumping data for table `ea_user_settings`
--

INSERT INTO `ea_user_settings` (`id_users`, `username`, `password`, `salt`, `working_plan`, `notifications`, `google_sync`, `google_token`, `google_calendar`, `sync_past_days`, `sync_future_days`) VALUES
(1, 'administrator', 'fa7fc34500cbed7c3546f8b223f10797f24ecc9ccbf0c2251c21ab965ebf19bf', 'e0a9e47fbf57babcf536e98bed783a9404b95b671cdcf9e391f68989fa3ac14f', NULL, 1, 0, NULL, NULL, 5, 5),
(2, 'g.clayton', 'a86f0c41be938c36eaedb3c4869c445fe8b7192188110f57bf86b55ac2252f05', '9b56eaa06cb0cc1c3bdce616291da4f53c2cc5d3449591bacb28099346333f05', '{"monday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"tuesday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"wednesday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"thursday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"friday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"saturday":null,"sunday":null}', 1, 0, NULL, NULL, 5, 5),
(3, 'c.nickolson', '7dcd5ed6a1cc42de678227aa8d528069761b218d181ff7ef446a49622c384782', '807349d6bacc35650205c66d664d4d414d150dec7f17dbba360752224bab73f4', '{"monday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"tuesday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"wednesday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"thursday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"friday":{"start":"09:00","end":"18:00","breaks":[{"start":"14:30","end":"15:00"}]},"saturday":null,"sunday":null}', 1, 0, NULL, NULL, 5, 5),
(4, 'n.rowland', '8cd1cc276a72f88e6d27372aecde8d87903a91fa33a6d2aceafbf2d110e4c9c2', '55b3a83cea1e3a5c4945fcb12a7621519705b3d09c4fa3408d912a832c8410a1', NULL, 1, 0, NULL, NULL, 5, 5);

--
-- Dumping data for table `ea_secretaries_providers`
--

INSERT INTO `ea_secretaries_providers` (`id_users_secretary`, `id_users_provider`) VALUES
(4, 3);


--
-- Dumping data for table `ea_service_categories`
--

INSERT INTO `ea_service_categories` (`id`, `name`, `description`) VALUES
(1, 'Quick Services', 'A collection of services that have small duration. '),
(2, 'Long Services', 'A collection of services that require more time. ');

--
-- Dumping data for table `ea_services`
--

INSERT INTO `ea_services` (`id`, `name`, `duration`, `price`, `currency`, `description`, `id_service_categories`) VALUES
(1, 'Best Quick Service ', 30, 50.00, '€', 'This is the best service and it requires only 30 minutes of your time!', 1),
(2, 'Another Q. Service', 45, 60.00, '€', 'This will be the best choice for someone that wants a balance between time and money.', 1),
(3, 'Best Long Service', 180, 100.00, '€', 'This long service will examine all the aspects of your problem. Definitely the best solution!', 2),
(4, 'Ungrouped Srv.', 45, 0.00, '', 'This category is not like the rest. It can''t be grouped. ', NULL);

--
-- Dumping data for table `ea_services_providers`
--

INSERT INTO `ea_services_providers` (`id_users`, `id_services`) VALUES
(2, 1),
(2, 2),
(3, 3),
(2, 4),
(3, 4);

/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

Hope you are trying to access the column id from the table ea_roles. If you want to access id only, no need to take all(*) the values, instead takes on id. Then update the function like this:

public function get_admin_role_id()
{
    $id = 0;
    $result = $this->db->select('id')->get_where('ea_roles', array('slug' => DB_SLUG_ADMIN));
    if ($result->num_rows() > 0) {
        $id = intval($result->row()->id);
    }
    return $id;
}