🏢 Company Employee Management System (SQL Project)

A beginner-friendly SQL-based project to manage employees and departments using MySQL. This system includes database creation, relational table setup with primary & foreign keys, CRUD operations, aggregate functions, and JOIN queries to simulate a real-world employee management system.

---

📌 Features

• ✅ Create & use company database
• ✅ Relational table setup (Employee, Department)
• ✅ Primary and foreign key constraints
• ✅ CRUD operations (Create, Read, Update, Delete)
• ✅ Aggregate functions: SUM(), AVG(), GROUP BY, HAVING
• ✅ JOIN queries to fetch employee and department info together

---

🧱 Database Schema

📂 Department Table

Column	Type	Constraints
dept_id	INT	PRIMARY KEY
dept_name	VARCHAR(50)	NOT NULL, UNIQUE

👨‍💼 Employee Table

Column	Type	Constraints
emp_id	INT	PRIMARY KEY
name	VARCHAR(100)	NOT NULL
salary	DECIMAL(10,2)	CHECK (salary > 0)
doj	DATE
dept_id	INT	FOREIGN KEY → Department(dept_id)

---

📊 Sample Queries

🔍 Basic SELECT

SELECT * FROM Department;

🔎 Filter & Sort

SELECT name, salary
FROM Employee
WHERE salary > 50000
ORDER BY salary DESC;

✏️ UPDATE

UPDATE Employee
SET salary = 65000
WHERE emp_id = 104;

🗑️ DELETE

DELETE FROM Employee
WHERE emp_id = 107;

📈 Aggregate

SELECT dept_id, SUM(salary) AS total_salary
FROM Employee
GROUP BY dept_id;

🤝 JOIN

SELECT e.emp_id, e.name AS employee_name, e.salary, d.dept_name AS department_name
FROM Employee e
JOIN Department d ON e.dept_id = d.dept_id;

---

📂 How to Run

1. Install MySQL and open any MySQL client (Workbench / CLI / phpMyAdmin)
2. Run the provided SQL script step by step
3. Query the tables to test

---

📣 Contribution

Feel free to fork this repo, add new queries, or create issue threads if you find bugs or want improvements!

---

🌟 Don't forget to

• ⭐ Star the repository
• 🍴 Fork it
• 📢 Share with friends & developers preparing for interviews
• 🔁 Keep practicing daily!

---

📩 Lets Connect

| |

---

"Practice makes perfect — keep querying until it's second nature!" 💪