SQL Modulo

The % operator returns the REMAINDER left over after division — useful for checking evenness, cycling through a fixed number of buckets, or spotting patterns in IDs.

What & Why

a % b returns whatever is left over after dividing a by b as many whole times as possible. A classic use: id % 2 = 0 checks whether a value is even.

See How It Works

BUSINESS QUESTION

Growth wants each user assigned to one of four deterministic analysis buckets.

id	created_at	country	channel	plan	activated_at	churned_at
101	2024-01-15 09:10:00+00	US	organic	pro	2024-01-16 14:25:00+00	NULL
102	2024-02-10 11:05:00+00	CA	paid	free	NULL	2024-03-20 10:00:00+00
103	2024-03-12 16:35:00+00	GB	referral	pro	2024-03-13 08:15:00+00	NULL
104	2024-04-01 13:20:00+00	US	organic	free	2024-04-03 12:00:00+00	NULL

EXAMPLE QUERY

SELECT
  id AS user_id,
  MOD(id, 4) AS user_bucket
FROM growth.users
ORDER BY user_id;

RESULT — exact output from the displayed Queryflo rows

user_id	user_bucket
101	1
102	2
103	3
104	0

The four user IDs occupy all four modulo buckets.

Intermediate business practice