DataBolt

All Lessons

Introduction to SQL

SQL Lesson 1: Your Sample Database

SQL Lesson 2: SELECT — Reading data

SQL Lesson 3: WHERE — Filtering rows

SQL Lesson 4: AND, OR, NOT

SQL Lesson 5: BETWEEN, IN, LIKE

SQL Lesson 6: NULL — The Mystery Value

SQL Lesson 7: ORDER BY

SQL Lesson 8: LIMIT & OFFSET

SQL Lesson 9: Aggregate Functions

SQL Lesson 10: GROUP BY

SQL Lesson 11: HAVING

SQL Lesson 12: INNER JOINs

SQL Lesson 13: LEFT JOINs

SQL Lesson 14: RIGHT JOINs

SQL Lesson 15: SELF JOINs

SQL Lesson 16: UNION JOINs

SQL Lesson 17: Joining Multiple Tables

SQL Lesson 18: Subqueries

SQL Lesson 19: CTEs (WITH)

SQL Lesson 20: CASE Statements

SQL Lesson 21: Window Functions

SQL Lesson 22: String Functions

SQL Lesson 23: Date & Time Functions

SQL Lesson 24: INSERT, UPDATE, DELETE

SQL Lesson 25: CREATE TABLE & DDL

SQL Lesson 26: Indexes & Performance

SQL Lesson 27: Transactions & ACID

SQL Lesson 28: SQL Execution Order

SQL Lesson 29: 50 Practice Problems

CHAPTER 9

LIMIT & OFFSET

Pagination — how every "Load More" button in every app works.

IN THIS CHAPTER

LIMIT N - GET only the top N rows
LIMIT + OFFSET for page-based pagination
The pagination formula every backend engineer uses

9.1 - Top N

Top 3 earners

SELECT name, salary 
FROM employees
ORDER BY salary DESC
LIMIT 3;

9.2 - Pagination with OFFSET

Page 2 of employees (3 per page)

-- Page formula: OFFSET = (page_number - 1) * page_size
SELECT name FROM employees
ORDER BY name LIMIT 3 OFFSET 3; -- Page 2

✅ Pro Tip: Always include ORDER BY when using LIMIT/OFFSET. Without ORDER BY, the database returns rows in an arbitrary order — pagination results will be inconsistent and unpredictable across queries.

💡 Engineering Insight: At scale, OFFSET-based pagination is inefficient — to get page 1000 the database still reads 999*page_size rows and throws them away. Senior engineers use 'keyset pagination' (WHERE id > last_seen_id) which is O(1) regardless of page number.

Exercise 👇

Exercise:

Tasks

1.👉Show only the first 3 employees.

2.Find top 2 highest paid employees.

3.Skip first 2 employees and show next 3 employees.

4.Sort employees by name and show 4 employees after skipping the first one.

5.Find 3 employees with high salaries after skipping top 2 highest paid employees.

Stuck? Read this task's