SQL Comparison Operators

The six symbols WHERE conditions are built from.

What & Why

Every basic WHERE condition uses one of six comparison operators. The operator tells PostgreSQL exactly how to compare a row’s value with the value in your condition.

Operator	Meaning
`=`	equal to
`!= or <>`	not equal to
`>`	greater than
`<`	less than
`>=`	greater than or equal to
`<=`	less than or equal to

See How It Works

Start with these four rows from marketing.campaigns. The condition keeps campaigns whose channel is not google_ads.

id	name	channel	spend	start_date
1	Spring Launch	google_ads	55000.00	2024-01-15
2	Retention Webinar	email	45000.00	2024-02-10
3	Finance Retargeting	linkedin	50000.00	2024-03-12
4	Enterprise Search	google_ads	60000.00	2024-04-01

EXAMPLE QUERY

SELECT name FROM marketing.campaigns WHERE channel != 'google_ads';

RESULT — channel != 'google_ads'

name
Retention Webinar
Finance Retargeting

The two google_ads rows fail the not-equal comparison, so only email and linkedin campaigns remain.

Now You Try

Practice this concept

Marketing wants low-score leads that need cleanup. Return leads with lead score below 40.

Available schema

marketing

Prefix tables with marketing.table_name.

idsourcelead_score

marketing.leads

Column	Type
id	integer
campaign_id	integer
email	text
created_at	timestamp with time zone
qualified_at	timestamp with time zone
converted_at	timestamp with time zone
lead_score	integer
source	text
country	text
archive_status	text

query.sql

Beginner business practice