--工资加500，OLD。SAL>2500 不加，NEW。SAL>2500 则改为2500；

SELECT * FROM EMP                                                                --加工资之前

CREATE OR REPLACE PROCEDURE SP_ADD (add IN number) is       --add参数接收传入的工资增幅

     --DECLARE
     --CURSOR emp_cur IS SELECT * FROM emp;
    
BEGIN
    
     FOR  sal_sum IN (SELECT * FROM emp) LOOP    --使用循环游标隐式打开游标emp_cur或    

                                                                                   --（SELECT * FROM emp)(在FOR循环中不需要声明此游标)
                                                                                   --自动从活动集获取行，然后在处理完所有行时关闭游标    
          IF sal_sum.sal > 2500 THEN                                             --逐行进行比较赋值
                UPDATE emp SET sal = sal_sum.sal WHERE empno = sal_sum.empno;
               
          ELSIF (sal_sum.sal + add) > 2500 THEN
                UPDATE emp SET sal = 2500 WHERE empno = sal_sum.empno;
               
          ELSE             
                UPDATE emp SET sal = sal_sum.sal + add  WHERE empno = sal_sum.empno;
          END IF;
         
     END LOOP;
    
END;

BEGIN
     SP_ADD(500);                                                                 --输入增资的幅度                                                                                                                     
END;

SELECT * FROM EMP                                                                 --加工资之后