Write clean, readable SQL
Formatting and style practices that keep SQL easy to read and review.
Clean, readable SQL is easier to debug, maintain, and review.
Formatting Guidelines
-- GOOD: Readable and well-formatted
SELECT
u.id,
u.name,
u.email,
COUNT(o.id) AS order_count,
SUM(o.total) AS total_spent
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE u.status = 'active'
AND u.created_at >= '2024-01-01'
GROUP BY u.id, u.name, u.email
HAVING COUNT(o.id) > 0
ORDER BY total_spent DESC
LIMIT 100;
-- BAD: Hard to read
SELECT u.id,u.name,u.email,COUNT(o.id) AS order_count,SUM(o.total) AS total_spent FROM users u LEFT JOIN orders o ON u.id=o.user_id WHERE u.status='active' AND u.created_at>='2024-01-01' GROUP BY u.id,u.name,u.email HAVING COUNT(o.id)>0 ORDER BY total_spent DESC LIMIT 100;Style Rules
1
Use UPPERCASE for SQL keywords (SELECT, FROM, WHERE)
2
Put each major clause on its own line
3
Use meaningful table aliases (u for users, not t1)
4
Align similar elements vertically when possible
5
Add comments for complex logic