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.

Now You Try

Practice this concept

Growth wants every user assigned to one of four deterministic remainder buckets.

Available schema

growth

Prefix tables with growth.table_name.

user_iduser_bucket

growth.users

Column	Type
id	integer
created_at	timestamp with time zone
country	text
channel	text
plan	text
activated_at	timestamp with time zone
churned_at	timestamp with time zone
legacy_user_code	text

query.sql

Intermediate business practice