N+1 Problem
N+1 occurs when you fetch N rows and then issue a separate query for each row. Fix by using JOINs, subqueries, or batch loading.
MySQL
Intermediate
4 min read
The N+1 Query Problem
Example
-- N+1 (one query per order)
SELECT id FROM orders; -- returns 100 rows
-- then for each row:
SELECT * FROM customers WHERE id = ?;
-- Fixed with JOIN
SELECT o.id, c.name
FROM orders o
JOIN customers c ON c.id = o.customer_id; Pro Tip
ORM eager loading (e.g., with()) translates to a JOIN or IN() query — always use it.