Using a CASE/WHEN/THEN/ELSE statement within an UPDATE query.

case-in-update.sql

UPDATE `organisations`
SET `description` = CASE id
  	WHEN 1 THEN 'something'
	WHEN 2 THEN 'something else'
  	WHEN 3 THEN 'we\'re on the third record still'
  	WHEN 5 THEN 'we\'ve jumped to record five'
 	WHEN 6 THEN '...'
	ELSE NULL
END