SQL. Select c CASE

Для корректировки меню пользователя:

UPDATE SYSUSER s 

SET s.MENU_ID = (SELECT DISTINCT CASE (SELECT count(1) FROM menu WHERE name ='PlanningMenu')

WHEN 1 THEN (SELECT m2.id FROM menu m2 WHERE m2.NAME = 'PlanningMenu')

ELSE (SELECT m3.id FROM menu m3 WHERE m3.NAME = 'RootMenu')

END

FROM menu)

WHERE s.USERNAME LIKE 'root';