ORDER BY

-- Ascending (A-Z, 0-9) - default
SELECT * FROM users ORDER BY name;
SELECT * FROM users ORDER BY name ASC;

-- Descending (Z-A, 9-0)
SELECT * FROM users ORDER BY created_at DESC;

-- Sort by country A-Z, then by name A-Z within each country
SELECT * FROM users 
ORDER BY country, name;

-- Mix directions
SELECT * FROM products 
ORDER BY category ASC, price DESC;

-- Most expensive first within each category
SELECT * FROM products 
ORDER BY category, price DESC;

-- Sort by calculated value
SELECT *, price * quantity AS total 
FROM order_items 
ORDER BY price * quantity DESC;

-- Sort by alias
SELECT *, price * quantity AS total 
FROM order_items 
ORDER BY total DESC;

-- Sort by column position (not recommended)
SELECT name, email, created_at FROM users 
ORDER BY 3 DESC;  -- Orders by 3rd column (created_at)

-- PostgreSQL: Control NULL position
SELECT * FROM users ORDER BY phone NULLS FIRST;
SELECT * FROM users ORDER BY phone NULLS LAST;

-- SQLite/MySQL: NULLs are smallest (first in ASC, last in DESC)
-- To put NULLs last in ascending order:
SELECT * FROM users 
ORDER BY phone IS NULL, phone ASC;

-- Custom priority order using CASE
SELECT * FROM orders 
ORDER BY 
    CASE status
        WHEN 'urgent' THEN 1
        WHEN 'pending' THEN 2
        WHEN 'processing' THEN 3
        WHEN 'completed' THEN 4
        ELSE 5
    END;