SQL CASE

SQL's if/then/else — lets a query make a decision for each row, and return a different value depending on the answer.

What & Why

CASE evaluates conditions from top to bottom and returns the first matching result. Here each saas.accounts.mrr value becomes a high, mid, or low reporting tier without changing the stored account row.

Branch order matters: mrr >= 200 must come before mrr >= 150, because every high-MRR account also satisfies the broader mid threshold.

See How It Works

BUSINESS QUESTION

SaaS leadership wants accounts bucketed by MRR tier.

id	name	plan	mrr	created_at	churned_at	country	employee_count	industry
1	Acme Labs	growth	240.00	2024-01-08 10:00:00+00	NULL	US	45	software
2	Northstar Co	starter	90.00	2024-02-12 09:30:00+00	2024-05-18 12:00:00+00	CA	18	services
3	Atlas Works	scale	480.00	2024-03-04 15:10:00+00	NULL	GB	120	manufacturing
4	Bright Path	growth	180.00	2024-04-19 11:45:00+00	NULL	US	62	education

EXAMPLE QUERY

SELECT
  name,
  mrr,
  CASE
    WHEN mrr >= 200 THEN 'high'
    WHEN mrr >= 150 THEN 'mid'
    ELSE 'low'
  END AS mrr_tier
FROM saas.accounts
ORDER BY id;

RESULT — exact output from the displayed Queryflo rows

name	mrr	mrr_tier
Acme Labs	240.00	high
Northstar Co	90.00	low
Atlas Works	480.00	high
Bright Path	180.00	mid

CASE classifies the four displayed saas.accounts rows in source order.

Now You Try

Practice this concept

SaaS leadership wants each account classified by MRR: high at 200 or more, mid at 150 or more, and low otherwise. Return name, mrr, and mrr_tier in account-id order.

Available schema

saas

Prefix tables with saas.table_name.

namemrrmrr_tier

saas.accounts

Column	Type
id	integer
name	text
plan	text
mrr	numeric
created_at	timestamp with time zone
churned_at	timestamp with time zone
country	text
employee_count	integer
industry	text
customer_segment_v2	text

query.sql

Intermediate business practice