pl/sql 声明有名异常

create or replace procedure exceptiontest(testvalues in integer) is
invalid_empno exception;
testvalue integer := testvalues;
begin
  if testvalue is null then
     raise invalid_empno;
  else
    dbms_output.put_line(testvalue);
  end if;
  exception
    when invalid_empno then
      dbms_output.put_line('testvalue is null');
end exceptiontest;

 测试代码：

begin
  -- Call the procedure
  exceptiontest(testvalues => :testvalues);
end;