Project Title: Library Management System
Database: library management system
This project demonstrates the implementation of a Library Management System using SQL. It includes creating and managing tables, performing CRUD operations, and executing advanced SQL queries. The goal is to showcase skills in database design, manipulation, and querying.
- Set up the Library Management System Database: Create and populate the database with tables for branches, employees, members, books, issued status, and return status.
- CRUD Operations: Perform Create, Read, Update, and Delete operations on the data.
- CTAS (Create Table As Select): Utilize CTAS to create new tables based on query results.
- Advanced SQL Queries: Develop complex queries to analyze and retrieve specific data.
- Database Creation: Created a database named
library_db. - Table Creation: Created tables for branches, employees, members, books, issued status, and return status. Each table includes relevant columns and relationships.
CREATE DATABASE library management system;
DROP TABLE IF EXISTS branch;
CREATE TABLE branch
(
branch_id VARCHAR(10) PRIMARY KEY,
manager_id VARCHAR(10),
branch_address VARCHAR(30),
contact_no VARCHAR(15)
);
-- Create table "Employee"
DROP TABLE IF EXISTS employees;
CREATE TABLE employees
(
emp_id VARCHAR(10) PRIMARY KEY,
emp_name VARCHAR(30),
position VARCHAR(30),
salary DECIMAL(10,2),
branch_id VARCHAR(10),
FOREIGN KEY (branch_id) REFERENCES branch(branch_id)
);
-- Create table "Members"
DROP TABLE IF EXISTS members;
CREATE TABLE members
(
member_id VARCHAR(10) PRIMARY KEY,
member_name VARCHAR(30),
member_address VARCHAR(30),
reg_date DATE
);
-- Create table "Books"
DROP TABLE IF EXISTS books;
CREATE TABLE books
(
isbn VARCHAR(50) PRIMARY KEY,
book_title VARCHAR(80),
category VARCHAR(30),
rental_price DECIMAL(10,2),
status VARCHAR(10),
author VARCHAR(30),
publisher VARCHAR(30)
);
-- Create table "IssueStatus"
DROP TABLE IF EXISTS issued_status;
CREATE TABLE issued_status
(
issued_id VARCHAR(10) PRIMARY KEY,
issued_member_id VARCHAR(30),
issued_book_name VARCHAR(80),
issued_date DATE,
issued_book_isbn VARCHAR(50),
issued_emp_id VARCHAR(10),
FOREIGN KEY (issued_member_id) REFERENCES members(member_id),
FOREIGN KEY (issued_emp_id) REFERENCES employees(emp_id),
FOREIGN KEY (issued_book_isbn) REFERENCES books(isbn)
);
-- Create table "ReturnStatus"
DROP TABLE IF EXISTS return_status;
CREATE TABLE return_status
(
return_id VARCHAR(10) PRIMARY KEY,
issued_id VARCHAR(30),
return_book_name VARCHAR(80),
return_date DATE,
return_book_isbn VARCHAR(50),
FOREIGN KEY (return_book_isbn) REFERENCES books(isbn)
);
- Create: Inserted sample records into the
bookstable. - Read: Retrieved and displayed data from various tables.
- Update: Updated records in the
employeestable. - Delete: Removed records from the
memberstable as needed.
Task 1. Create a New Book Record -- "978-1-60129-456-2', 'To Kill a Mockingbird', 'Classic', 6.00, 'yes', 'Harper Lee', 'J.B. Lippincott & Co.')"
INSERT INTO books(isbn, book_title, category, rental_price, status, author, publisher)
VALUES('978-1-60129-456-2', 'To Kill a Mockingbird', 'Classic', 6.00, 'yes', 'Harper Lee', 'J.B. Lippincott & Co.');
SELECT * FROM books;Task 2: Update an Existing Member's Address
UPDATE members
SET member_address = '125 Oak St'
WHERE member_id = 'C103';Task 3: Delete a Record from the Issued Status Table -- Objective: Delete the record with issued_id = 'IS121' from the issued_status table.
DELETE FROM issued_status
WHERE issued_id = 'IS121';Task 4: Retrieve All Books Issued by a Specific Employee -- Objective: Select all books issued by the employee with emp_id = 'E101'.
SELECT * FROM issued_status
WHERE issued_emp_id = 'E101'Task 5: List Members Who Have Issued More Than One Book -- Objective: Use GROUP BY to find members who have issued more than one book.
SELECT
issued_emp_id,
COUNT(*)
FROM issued_status
GROUP BY 1
HAVING COUNT(*) > 1- Task 6: Create Summary Tables: Used CTAS to generate new tables based on query results - each book and total book_issued_cnt**
CREATE TABLE book_issued_cnt AS
SELECT b.isbn, b.book_title, COUNT(ist.issued_id) AS issue_count
FROM issued_status as ist
JOIN books as b
ON ist.issued_book_isbn = b.isbn
GROUP BY b.isbn, b.book_title;The following SQL queries were used to address specific questions:
Task 7. Retrieve All Books in a Specific Category:
SELECT * FROM books
WHERE category = 'Classic';- Task 8: Find Total Rental Income by Category:
SELECT
b.category,
SUM(b.rental_price),
COUNT(*)
FROM
issued_status as ist
JOIN
books as b
ON b.isbn = ist.issued_book_isbn
GROUP BY 1- List Members Who Registered in the Last 180 Days:
SELECT * FROM members
WHERE reg_date >= CURRENT_DATE - INTERVAL '180 days';- List Employees with Their Branch Manager's Name and their branch details:
SELECT
e1.emp_id,
e1.emp_name,
e1.position,
e1.salary,
b.*,
e2.emp_name as manager
FROM employees as e1
JOIN
branch as b
ON e1.branch_id = b.branch_id
JOIN
employees as e2
ON e2.emp_id = b.manager_idTask 11. Create a Table of Books with Rental Price Above a Certain Threshold:
CREATE TABLE expensive_books AS
SELECT * FROM books
WHERE rental_price > 7.00;Task 12: Retrieve the List of Books Not Yet Returned
SELECT * FROM issued_status as ist
LEFT JOIN
return_status as rs
ON rs.issued_id = ist.issued_id
WHERE rs.return_id IS NULL;Task 13: Identify Members with Overdue Books
Write a query to identify members who have overdue books (assume a 30-day return period). Display the member's_id, member's name, book title, issue date, and days overdue.
SELECT
ist.issued_member_id,
m.member_name,
bk.book_title,
ist.issued_date,
-- rs.return_date,
CURRENT_DATE - ist.issued_date as over_dues_days
FROM issued_status as ist
JOIN
members as m
ON m.member_id = ist.issued_member_id
JOIN
books as bk
ON bk.isbn = ist.issued_book_isbn
LEFT JOIN
return_status as rs
ON rs.issued_id = ist.issued_id
WHERE
rs.return_date IS NULL
AND
(CURRENT_DATE - ist.issued_date) > 30
ORDER BY 1Task 14: Update Book Status on Return
Write a query to update the status of books in the books table to "Yes" when they are returned (based on entries in the return_status table).
CREATE OR REPLACE PROCEDURE add_return_records(p_return_id VARCHAR(10), p_issued_id VARCHAR(10), p_book_quality VARCHAR(10))
LANGUAGE plpgsql
AS $$
DECLARE
v_isbn VARCHAR(50);
v_book_name VARCHAR(80);
BEGIN
-- all your logic and code
-- inserting into returns based on users input
INSERT INTO return_status(return_id, issued_id, return_date, book_quality)
VALUES
(p_return_id, p_issued_id, CURRENT_DATE, p_book_quality);
SELECT
issued_book_isbn,
issued_book_name
INTO
v_isbn,
v_book_name
FROM issued_status
WHERE issued_id = p_issued_id;
UPDATE books
SET status = 'yes'
WHERE isbn = v_isbn;
RAISE NOTICE 'Thank you for returning the book: %', v_book_name;
END;
$$
-- Testing FUNCTION add_return_records
issued_id = IS135
ISBN = WHERE isbn = '978-0-307-58837-1'
SELECT * FROM books
WHERE isbn = '978-0-307-58837-1';
SELECT * FROM issued_status
WHERE issued_book_isbn = '978-0-307-58837-1';
SELECT * FROM return_status
WHERE issued_id = 'IS135';
-- calling function
CALL add_return_records('RS138', 'IS135', 'Good');
-- calling function
CALL add_return_records('RS148', 'IS140', 'Good');
Task 15: Branch Performance Report
Create a query that generates a performance report for each branch, showing the number of books issued, the number of books returned, and the total revenue generated from book rentals.
CREATE TABLE branch_reports
AS
SELECT
b.branch_id,
b.manager_id,
COUNT(ist.issued_id) as number_book_issued,
COUNT(rs.return_id) as number_of_book_return,
SUM(bk.rental_price) as total_revenue
FROM issued_status as ist
JOIN
employees as e
ON e.emp_id = ist.issued_emp_id
JOIN
branch as b
ON e.branch_id = b.branch_id
LEFT JOIN
return_status as rs
ON rs.issued_id = ist.issued_id
JOIN
books as bk
ON ist.issued_book_isbn = bk.isbn
GROUP BY 1, 2;
SELECT * FROM branch_reports;Task 16: CTAS: Create a Table of Active Members
Use the CREATE TABLE AS (CTAS) statement to create a new table active_members containing members who have issued at least one book in the last 2 months.
CREATE TABLE active_members
AS
SELECT * FROM members
WHERE member_id IN (SELECT
DISTINCT issued_member_id
FROM issued_status
WHERE
issued_date >= CURRENT_DATE - INTERVAL '2 month'
)
;
SELECT * FROM active_members;
Task 17: Find Employees with the Most Book Issues Processed
Write a query to find the top 3 employees who have processed the most book issues. Display the employee name, number of books processed, and their branch.
SELECT
e.emp_name,
b.*,
COUNT(ist.issued_id) as no_book_issued
FROM issued_status as ist
JOIN
employees as e
ON e.emp_id = ist.issued_emp_id
JOIN
branch as b
ON e.branch_id = b.branch_id
GROUP BY 1, 2Task 18: Identify Members Issuing High-Risk Books
Write a query to identify members who have issued books more than twice with the status "damaged" in the books table. Display the member name, book title, and the number of times they've issued damaged books.
Task 19: Stored Procedure Objective: Create a stored procedure to manage the status of books in a library system. Description: Write a stored procedure that updates the status of a book in the library based on its issuance. The procedure should function as follows: The stored procedure should take the book_id as an input parameter. The procedure should first check if the book is available (status = 'yes'). If the book is available, it should be issued, and the status in the books table should be updated to 'no'. If the book is not available (status = 'no'), the procedure should return an error message indicating that the book is currently not available.
CREATE OR REPLACE PROCEDURE issue_book(p_issued_id VARCHAR(10), p_issued_member_id VARCHAR(30), p_issued_book_isbn VARCHAR(30), p_issued_emp_id VARCHAR(10))
LANGUAGE plpgsql
AS $$
DECLARE
-- all the variabable
v_status VARCHAR(10);
BEGIN
-- all the code
-- checking if book is available 'yes'
SELECT
status
INTO
v_status
FROM books
WHERE isbn = p_issued_book_isbn;
IF v_status = 'yes' THEN
INSERT INTO issued_status(issued_id, issued_member_id, issued_date, issued_book_isbn, issued_emp_id)
VALUES
(p_issued_id, p_issued_member_id, CURRENT_DATE, p_issued_book_isbn, p_issued_emp_id);
UPDATE books
SET status = 'no'
WHERE isbn = p_issued_book_isbn;
RAISE NOTICE 'Book records added successfully for book isbn : %', p_issued_book_isbn;
ELSE
RAISE NOTICE 'Sorry to inform you the book you have requested is unavailable book_isbn: %', p_issued_book_isbn;
END IF;
END;
$$
-- Testing The function
SELECT * FROM books;
-- "978-0-553-29698-2" -- yes
-- "978-0-375-41398-8" -- no
SELECT * FROM issued_status;
CALL issue_book('IS155', 'C108', '978-0-553-29698-2', 'E104');
CALL issue_book('IS156', 'C108', '978-0-375-41398-8', 'E104');
SELECT * FROM books
WHERE isbn = '978-0-375-41398-8'
Task 20: Create Table As Select (CTAS) Objective: Create a CTAS (Create Table As Select) query to identify overdue books and calculate fines.
Description: Write a CTAS query to create a new table that lists each member and the books they have issued but not returned within 30 days. The table should include: The number of overdue books. The total fines, with each day's fine calculated at $0.50. The number of books issued by each member. The resulting table should show: Member ID Number of overdue books Total fines
- Database Schema: Detailed table structures and relationships.
- Data Analysis: Insights into book categories, employee salaries, member registration trends, and issued books.
- Summary Reports: Aggregated data on high-demand books and employee performance.
This project demonstrates the application of SQL skills in creating and managing a library management system. It includes database setup, data manipulation, and advanced querying, providing a solid foundation for data management and analysis.