You’ve learned the SQL basics, joins, keys, and how to normalize a database. Now it’s time to put that knowledge into action with a hands-on mini project.

In this beginner-friendly project, you’ll:

• Create tables for students, courses, and enrollments
• Insert sample data
• Write basic queries
• Normalize and connect tables using keys

Let’s build your first real database step by step.

 Step 1: Plan Your Tables

We’ll create three related tables:

1. students — holds basic student info
2. courses — stores course details
3. enrollments — links students to courses (many-to-many)

This structure follows best practices for relational design.

 Table Structure Overview

Table: students

Column	Data Type	Description
student_id	INT PRIMARY KEY	Unique student ID
name	VARCHAR(50)	Student’s full name
email	VARCHAR(100)	Email address

Table: courses

Column	Data Type	Description
course_id	INT PRIMARY KEY	Unique course ID
course_name	VARCHAR(100)	Name of the course

Table: enrollments

Column	Data Type	Description
enrollment_id	INT PRIMARY KEY	Unique enrollment ID
student_id	INT	Foreign key → students
course_id	INT	Foreign key → courses
date_enrolled	DATE	Enrollment date

We’re using primary and foreign keys to connect the tables.

 Step 2: Create the Tables

CREATE TABLE students (

student_id INT PRIMARY KEY,

name VARCHAR(50),

email VARCHAR(100)

);

 

CREATE TABLE courses (

course_id INT PRIMARY KEY,

course_name VARCHAR(100)

);

 

CREATE TABLE enrollments (

enrollment_id INT PRIMARY KEY,

student_id INT,

course_id INT,

date_enrolled DATE,

FOREIGN KEY (student_id) REFERENCES students(student_id),

FOREIGN KEY (course_id) REFERENCES courses(course_id)

);

 Step 3: Insert Sample Data

INSERT INTO students VALUES

(1, ‘Ali’, ‘ali@example.com’),

(2, ‘Zara’, ‘zara@example.com’),

(3, ‘Ayesha’, ‘ayesha@example.com’);

 

INSERT INTO courses VALUES

(101, ‘Math’),

(102, ‘Physics’),

(103, ‘Computer Science’);

 

INSERT INTO enrollments VALUES

(1, 1, 101, ‘2025-06-01’),

(2, 1, 102, ‘2025-06-05’),

(3, 2, 103, ‘2025-06-10’);

If you’re unsure how to insert or update, revisit SQL basics.

 Step 4: Query the Database

1. Show all students:

SELECT * FROM students;

2. List all enrollments with student names and course names:

SELECT s.name, c.course_name, e.date_enrolled

FROM enrollments e

JOIN students s ON e.student_id = s.student_id

JOIN courses c ON e.course_id = c.course_id;

This is an example of an INNER JOIN.

3. Find students enrolled in more than one course:

SELECT student_id, COUNT(*) as course_count

FROM enrollments

GROUP BY student_id

HAVING COUNT(*) > 1;

 What You’ve Practiced

• Creating normalized tables using 1NF–3NF
• Using primary/foreign keys to enforce structure
• Writing JOINs and GROUP BY queries
• Designing a scalable, real-world database

Got stuck anywhere or want to share your results?
Leave a comment below — I’d love to hear how your student database project went!