 -- Table structure for table `subjects`
 --
 
-CREATE TABLE `subjects` (
-  `subject_id` int(8) UNSIGNED NOT NULL,
+CREATE TABLE IF NOT EXISTS `subjects` (
+  `subject_id` int(8) UNSIGNED NOT NULL AUTO_INCREMENT,
   `subject_code` varchar(50) NOT NULL,
   `subject_description` varchar(100) NOT NULL,
   `created_at` bigint(11) NOT NULL,

-- Table structure for table `users`
--

CREATE TABLE `users` (
  `id` mediumint(8) UNSIGNED NOT NULL,
  `ip_address` varbinary(16) NOT NULL,
  `username` varchar(100) NOT NULL,
  `password` varchar(80) NOT NULL,

-- Table structure for table `rooms`
--

CREATE TABLE IF NOT EXISTS `rooms` (
  `room_id` int(8) UNSIGNED NOT NULL AUTO_INCREMENT,
  `room_number` varchar(50) NOT NULL,
  `room_capacity` int(2) NOT NULL,
  `created_at` int(11) NOT NULL,
