编写pl/sql代码来计算7788和7782员工的工作年限
然后打印经验最老的员工的信息。
使用引用%rowtype编写代码。
使用适当的日期和数字函数来计算体验。
打印结果如下：

The Oldest Employee Is: CLARK
His Years of Experience: 38

这是我的答案不知道怎么了或者有什么问题

DECLARE 
    EmpInfo emp%ROWTYPE; 
    MaxEx number :=0; 
    EmployeeName emp.ename%TYPE; 
    ExNumber number; 
cursor oldex is select * from emp where EMP.EMPNO = 7788 or EMP.EMPNO = 7782 ; 
BEGIN OPEN oldex; 
    LOOP FETCH oldex into EmpInfo; 
    EXIT WHEN oldex%notfound; 
    ExNumber := (TO_NUMBER(TO_CHAR(SYSDATE,'YYYY')) - TO_NUMBER(TO_CHAR(EmpInfo.hiredate,'YYYY'))); 
    if ExNumber > MaxEx then MaxEx := ExNumber; 
    EmployeeName := EmpInfo.ename; 
END IF; 
END LOOP;

dbms_output.put_line('The oldest employee is: '|| EmployeeName); 
dbms_output.put_line('His year experiance is: '|| MaxEx); 
CLOSE oldex; 
END;