SQL Tutorial | KNOWe Platform

KNOWe Learning Module

Learn SQL

Master Structured Query Language to work with databases, retrieve data, and manage structured records.

Start Learning Jump to Mini Project

Why Learn SQL?

Database Skill

Store, retrieve, and organize structured information efficiently.

High Employability

Used in office systems, websites, analytics, and data roles worldwide.

📋 Sample Database: Students Table

Throughout this tutorial, we'll use a sample students table:

id	name	age	course	grade
1	Aarav Sharma	21	Computer Science	A
2	Priya Singh	20	Mathematics	B+
3	Rahul Verma	22	Physics	A-
4	Neha Gupta	19	Computer Science	B
5	Vikram Patel	23	Chemistry	C+

SQL Syntax

SQL statements are commands sent to a database. Try it yourself!

Try SQL Code

Query Results

SELECT Statement

SELECT retrieves data from a table. Try different queries!

WHERE Clause

WHERE filters records using conditions. Try different filters!

ORDER BY Clause

ORDER BY sorts query results. Try sorting!

INSERT INTO Statement

INSERT INTO adds new records to a table.

UPDATE Statement

UPDATE changes existing records. Always use WHERE to specify which records to update!

DELETE Statement

DELETE removes records from a table. Use with caution!

Warning: Always use WHERE with DELETE/UPDATE to avoid modifying all records!

🎯 Mini Project: Student Management System

-- ============================================
-- STUDENT MANAGEMENT SYSTEM - Complete Example
-- ============================================

-- 1. Create a new table
CREATE TABLE IF NOT EXISTS students_new (
    id INTEGER PRIMARY KEY,
    name TEXT,
    age INTEGER,
    course TEXT,
    grade TEXT,
    enrollment_date DATE
);

-- 2. Insert sample records
INSERT INTO students_new VALUES 
(1, 'Raj Kumar', 21, 'Computer Science', 'A', '2024-01-15'),
(2, 'Simran Kaur', 20, 'Data Science', 'B+', '2024-01-20'),
(3, 'Amit Patel', 22, 'Mathematics', 'A-', '2024-02-01'),
(4, 'Neha Singh', 19, 'Physics', 'B', '2024-02-10');

-- 3. Query - All students
SELECT '=== ALL STUDENTS ===' AS '';
SELECT * FROM students_new;

-- 4. Query - Filter by grade
SELECT '=== STUDENTS WITH GRADE A ===' AS '';
SELECT name, grade FROM students_new WHERE grade LIKE 'A%';

-- 5. Query - Age statistics
SELECT '=== AGE STATISTICS ===' AS '';
SELECT AVG(age) AS avg_age, MAX(age) AS max_age, MIN(age) AS min_age 
FROM students_new;

-- 6. Update - Promote student
UPDATE students_new 
SET grade = 'A+' 
WHERE name = 'Raj Kumar';

-- 7. Insert - New student
INSERT INTO students_new VALUES (5, 'Kavya Sharma', 21, 'Computer Science', 'A', '2024-03-01');

-- 8. Final report
SELECT '=== FINAL STUDENT REPORT ===' AS '';
SELECT name, course, grade, 
    CASE 
        WHEN grade LIKE 'A%' THEN 'Excellent'
        WHEN grade LIKE 'B%' THEN 'Good'
        ELSE 'Average'
    END AS performance
FROM students_new
ORDER BY grade;

SELECT 'Total Students: ' || COUNT(*) AS summary FROM students_new;

SQL Assessment

Test your understanding of SQL fundamentals.

1. Which SQL command is used to retrieve data?
SELECT CREATE DELETE

2. Which clause is used to filter records?
ORDER BY WHERE GROUP

3. SQL is used to work with databases.
True False

Complete the quiz and click submit.

Learner Progress

Track completion of this SQL module.

Course Progress0%

Intro & Why SQL

SELECT & WHERE

ORDER BY & Sorting

INSERT, UPDATE, DELETE

Mini Project (Student System)

Assessment Completed

Next Steps

✓ Practice sample queries on tables like students, employees, products
✓ Master SELECT, WHERE, ORDER BY, and aggregate functions (COUNT, AVG, SUM)
✓ Write your own INSERT, UPDATE, and DELETE statements
✓ Continue to JOINs, GROUP BY, subqueries, and database design
✓ Learn about primary keys, foreign keys, and normalization