检索 SELECT 中的多个属性

Retrieving multiple attributes in SELECT

在PL/SQL函数中,我试图用下面的代码编写一个函数:

CREATE OR REPLACE FUNCTION Lib_func(id number,dateToday date)
RETURN number IS retVal number(1);

myBorrower number;
myBook number;

BEGIN

SELECT P.book_id INTO myBook, P.request_id INTO myBorrower
    FROM My_requests P
    WHERE P.book_id = book_id AND ROWNUM <=1;

//some if condition which updates value of retVal
RETURN retVal;
END;
/

问题是这导致我编译时出错。如果我删除第二个东西(即 P.request_id INTO myBorrower)然后错误被删除。 我不能在一个查询中同时选择这两个东西吗?

选择多个变量的语法是:

SELECT P.book_id , P.request_id
INTO myBook,myBorrower
FROM My_requests P
WHERE P.book_id = book_id AND ROWNUM <=1;