SQL — Order By

Basic ORDER BY

-- Ascending (default)
SELECT * FROM users ORDER BY name;

-- Descending
SELECT * FROM users ORDER BY name DESC;

Multiple columns

SELECT * FROM users
ORDER BY age DESC, name ASC;

ORDER BY with expressions

SELECT name, price, price * 0.9 AS discounted
FROM products
ORDER BY price * 0.9;

ORDER BY column number

SELECT name, age, email
FROM users
ORDER BY 2 DESC; -- Sort by age

ORDER BY with NULL

-- NULLs first (PostgreSQL)
SELECT * FROM users ORDER BY phone NULLS FIRST;

-- NULLs last (PostgreSQL)
SELECT * FROM users ORDER BY phone NULLS LAST;

-- MySQL: NULLs are treated as lowest value
SELECT * FROM users ORDER BY phone;

ORDER BY with LIMIT

-- Top 5 oldest users
SELECT * FROM users
ORDER BY age DESC
LIMIT 5;

-- Top 10% (PostgreSQL)
SELECT * FROM users
ORDER BY age DESC
FETCH FIRST 10 PERCENT ROWS ONLY;

Mini Practice

Write SQL code that:

1. Sorts by a single column
2. Sorts by multiple columns
3. Orders with NULL handling
4. Combines ORDER BY with LIMIT

Up Next

In the next lesson, you'll learn about Group By — aggregating data.