SQL · Reading data

coalesce

Returns the first non-null argument.

sqlRunnable example sql course

Syntax

coalesce(value, fallback)

Example

Open in the lab

WITH lessons(note) AS (VALUES (NULL), ('ready'))
SELECT COALESCE(note, 'no note') AS note FROM lessons;

Reference pages are the quick answer. The course explains the why, shows the full example and ends with a challenge.