changed data structure

backend/scheme.sql

@@ -0,0 +1,54 @@
+CREATE TABLE users (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    username VARCHAR(100) NOT NULL UNIQUE,
+    password VARCHAR(255) NOT NULL
+);
+
+CREATE TABLE items (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    item_name VARCHAR(255) NOT NULL UNIQUE,
+    can_borrow_role VARCHAR(255) NOT NULL
+);
+
+CREATE TABLE loans (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    username VARCHAR(100) NOT NULL,
+    loan_code INT(6) NOT NULL UNIQUE,
+    start_date TIMESTAMP NOT NULL,
+    end_date TIMESTAMP NOT NULL,
+    returned_date TIMESTAMP,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE lockers (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    item VARCHAR(255) NOT NULL UNIQUE,
+    locker_number INT NOT NULL UNIQUE
+);
+
+
+-- Mock data
+
+-- Users
+INSERT INTO users (username, password) VALUES
+('alice', 'password123'),
+('bob', 'securepass'),
+('charlie', 'charliepwd');
+
+-- Items
+INSERT INTO items (item_name, can_borrow_role) VALUES
+('Laptop', 'student'),
+('Projector', 'teacher'),
+('Tablet', 'student,teacher');
+
+-- Loans
+INSERT INTO loans (username, loan_code, start_date, end_date, returned_date) VALUES
+('alice', 100001, '2025-08-01 09:00:00', '2025-08-10 17:00:00', NULL),
+('bob', 100002, '2025-08-05 10:00:00', '2025-08-12 15:00:00', '2025-08-12 14:30:00'),
+('charlie', 100003, '2025-08-07 11:00:00', '2025-08-15 16:00:00', NULL);
+
+-- Lockers
+INSERT INTO lockers (item, locker_number) VALUES
+('Laptop', 101),
+('Projector', 102),
+('Tablet', 103);