# SQL Implementation ## Database Creation CREATE DATABASE library; ## Table creation CREATE TABLE book ( isbn INT PRIMARY KEY, title VARCHAR(100) NOT NULL, author VARCHAR(100) NOT NULL, year INT NOT NULL ); CREATE TABLE member ( member_id INT PRIMARY KEY, name VARCHAR(50), email VARCHAR(50) NOT NULL ); CREATE TABLE loan ( isbn INT REFERENCES book(isbn), member_id INT REFERENCES member(member_id), loan_date DATE NOT NULL, return_date DATE NOT NULL, PRIMARY_KEY(isbn, member_id) ); SHOW TABLES; ## CRUD Queries ### Insert at least 3 books and 2 members INSERT INTO book VALUES (9781927077030, 'The Three Principles of the People - San Min Chu I', 'Sun Yat-Sen', 2011), (9780717802418, 'The Communist Manifesto', 'Karl Marx, Friedrich Engels', ''), (9780131103627, 'C Programming Language, 2nd Edition', 'Brian W. Kernighan, Dennis M. Ritchie'); INSERT INTO member VALUES (10000001, 'Winnie The Pooh', 'winniethepooh@gmail.com'), (10000002, 'Gary the Dinosaur', 'garythedino@gmail.com'); SELECT * FROM book; SELECT * FROM member; ### Insert 2 loans INSERT INTO loan VALUES (9780131103627, 10000001, '2025-09-11', '2025-09-14'), (9781927077030, 10000002, '2025-08-10, '2025-10-12') SELECT * FROM loan; ### Select all loans with member name and book title (JOIN) SELECT B.title, M.name FROM loans L INNER JOIN book B ON B.isbn = L.isbn, INNER JOIN member M ON M.member_id = L.member_id; ### Update one Loan's ReturnDate UPDATE loan SET return_date = '2025-11-10' WHERE isbn = 9781927077030 AND member_id = 10000002; SELECT * FROM loan; ### Delete one loan record DELETE FROM loan WHERE isbn = 9870131103627 AND member_id = 10000001; SELECT * FROM loan;