这个示例将变量new_sal传递给过程adjust_salary。该过程将一个值赋给相应的形式参
数sal。由于sal是一个 IN OUT 参数,变量new_sal在过程结束后保留了赋值。
DECLARE
done BOOLEAN; -- Initial value is NULL by default
counter NUMBER := 0;
BEGIN
done := FALSE; -- Assign literal value
WHILE done != TRUE -- Compare to literal value
LOOP
counter := counter + 1;
done := (counter > 500); -- Assign value of BOOLEAN expression
END LOOP;
END;