Query Select Oracle PLSQL Tutorial

Searched CASE expressions use conditions to determine the returned value and have the following syntax:

CASE
  WHEN condition1 THEN result1
  WHEN condition2 THEN result2
  ...
  WHEN conditionN THEN resultN
  ELSE default_result
END
where
condition1, condition2, ..., conditionN are the expressions to be evaluated.
result1, result2, ..., resultN are the returned results (one for each possible condition).
If condition1 is true, result1 is returned, and so on.
default_result is the default result returned when no true condition is found.