SQL WHERE vs HAVING

They look similar and both filter — but they operate at completely different stages of the query, and mixing up when to use which is one of the most common intermediate-level mistakes.

What & Why

Both WHERE and HAVING remove rows from a result — that's what makes them easy to confuse. The difference is entirely about when each one runs, relative to GROUP BY:

A useful way to remember it: if the condition needs an aggregate function (COUNT, SUM, AVG, and so on) to even make sense, it belongs in HAVING. If it's checking a plain column value on an individual row, it belongs in WHERE. A single query can absolutely use both together — and when it does, the order they run in genuinely changes the result, not just the syntax.

See How It Works

BUSINESS QUESTION

Marketing wants channels with at least two campaigns whose spend is 50,000 or more.

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 WHERE filter rows before HAVING filters groupsStage 1 of 4

-- start with every marketing.campaigns row

id	name	channel	spend	WHERE result
1	Spring Launch	google_ads	55,000	WAIT
2	Retention Webinar	email	45,000	WAIT
3	Finance Retargeting	linkedin	50,000	WAIT
4	Enterprise Search	google_ads	60,000	WAIT

WHERE and HAVING have not run yet; all four campaigns are source rows.

EXAMPLE QUERY

SELECT
  channel,
  COUNT(*) AS qualifying_campaigns
FROM marketing.campaigns
WHERE spend >= 50000
GROUP BY channel
HAVING COUNT(*) >= 2
ORDER BY qualifying_campaigns DESC, channel;

Now You Try

Practice this concept

Marketing wants channels with at least two campaigns whose spend is 50,000 or more.

Available schema

marketing

Prefix tables with marketing.table_name.

channelqualifying_campaigns

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