Description of the illustration simple_case_expression.eps

CASE selector
  WHEN (selector_value | dangling_predicate)
    [, selector_value | dangling_predicate]... THEN result_value
      [ WHEN (selector_value | dangling_predicate) 
        [, selector_value | dangling_predicate]... THEN result_value]... 
  [ ELSE result_value]
END