Oracle触发器+包+过程+函数

使用PL/SQL针对Scott模式中的数据完成以下任务：
1. 编写一个数据库触发器，当任何时候某个部门从"dept"中删除时，该触发器将从"emp"表中 删除该部门的所有雇员。
2. 编写一个数据包，它有两个函数和两个过程以操作"emp"表。该数据包要执行的任务为：
①插入一个新雇员；
②删除一个现有雇员；
③显示指定雇员的整体薪水；
④显示指定雇员所在部门名称。
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1.create or replace trigger Trigger_dept_emp
  before delete on dept 
  for each row
begin
  delete from emp where deptno=:old.deptno;
end Trigger_dept_emp;
/
2.create or replace package Emp_Operate is

procedure insert_emp(   P_EMPNO NUMBER,                                                                      
                        P_ENAME VARCHAR2,
                        P_JOB VARCHAR2,
                        P_MGR NUMBER,
                        P_HIREDATE VARCHAR2,
                        P_SAL NUMBER,
                        P_COMM NUMBER,
                        P_DEPTNO NUMBER);
procedure delete_emp(P_EMPNO NUMBER);

function show_sal(F_EMPNO in NUMBER)
   return NUMBER;
  
function show_dname(F_EMPNO in NUMBER)  
  return varchar2;
end Emp_Operate;
/
create or replace package body Emp_Operate is
  procedure insert_emp(   P_EMPNO NUMBER,                                                                      
                          P_ENAME VARCHAR2,
                          P_JOB VARCHAR2,
                          P_MGR NUMBER,
                          P_HIREDATE VARCHAR2,
                          P_SAL NUMBER,
                          P_COMM NUMBER,
                          P_DEPTNO NUMBER) is
  begin
      insert into emp values(P_EMPNO,P_ENAME,P_JOB,P_MGR,to_date(P_HIREDATE,'yyyy-mm-dd'),P_SAL,P_COMM,P_DEPTNO);
  end insert_emp;
 
  procedure delete_emp(P_EMPNO NUMBER) is
    begin
      delete from emp where empno=P_EMPNO;
    end delete_emp;
   
  function show_sal(F_EMPNO in  NUMBER)
   return NUMBER is
   F_SAL NUMBER;
  begin
    select SAL INTO F_SAL from EMP where EMPNO=F_EMPNO;
    return F_SAL;
  end show_sal;
  function show_dname(F_EMPNO in NUMBER)
   return   varchar2 is
   F_DNAME varchar2(20);
   begin
     select DNAME into F_DNAME from DEPT,EMP where DEPT.DEPTNO=EMP.DEPTNO AND EMP.EMPNO=F_EMPNO;
     return F_DNAME;
  end show_dname;
end Emp_Operate;
/
调用方法不再赘述