SQL GROUP BY Multiple Columns

List more than one column to group — a new group forms for every distinct COMBINATION of values, not just each column separately.

What & Why

Grouping by one column answers "one number per channel." Sometimes that's not specific enough — "one number per channel, split further by whether the campaign is still active" needs a second grouping column. List both columns, separated by a comma: GROUP BY channel, status.

The important mental model here: Postgres doesn't group by channel and then separately by status — it groups by the unique combination of both values together. Two rows only land in the same group if they match on every listed column, not just one of them. IT-and-active is a different group from IT-and-inactive, even though both share the same channel value.

See How It Works

BUSINESS QUESTION

Marketing wants campaign counts for every channel and status combination.

id	name	channel	spend	start_date	end_date	status	target_segment
1	Spring Launch	google_ads	55000.00	2024-01-15	2024-03-31	active	smb
2	Retention Webinar	email	45000.00	2024-02-10	2024-04-15	active	enterprise
3	Finance Retargeting	linkedin	50000.00	2024-03-12	2024-05-31	active	enterprise
4	Enterprise Search	google_ads	60000.00	2024-04-01	2024-06-30	active	enterprise

Watch campaign rows enter a channel + status groupCampaign 1 of 4

GROUP BY channel, status · COUNT(*)

id	name	channel	status	group key	state
1	Spring Launch	google_ads	active	google_ads · active	CURRENT
2	Retention Webinar	email	active	email · active	WAIT
3	Finance Retargeting	linkedin	active	linkedin · active	WAIT
4	Enterprise Search	google_ads	active	google_ads · active	WAIT

channel	status	campaign_count
google_ads	active	1

Spring Launch contributes to the google_ads · active group; the second google_ads row visibly increments the same bucket.

EXAMPLE QUERY

SELECT
  channel,
  status,
  COUNT(*) AS campaign_count
FROM marketing.campaigns
GROUP BY channel, status
ORDER BY channel, status;

Now You Try

Practice this concept

Marketing wants campaign counts for every channel and status combination.

Available schema

marketing

Prefix tables with marketing.table_name.

channelstatuscampaign_count

marketing.campaigns

Column	Type
id	integer
name	text
channel	text
spend	numeric
start_date	date
end_date	date
status	text
target_segment	text
legacy_id	text

query.sql

Intermediate business practice