oracle初探秘之维护表

近来在自学PLSQL,接触时间尚浅,写了一个维护SCOTT名下dept表的触发器和存储过程.就当练习了.欢迎大牛们指出缺点.

这是维护表的表结构

 create table dept_history(
 id number primary key,
 deptno number(4),
 dname varchar2(14),
 loc varchar2(13));

删除时的触发器:

create or replace trigger add_dept_his  
  before delete on dept   
  for each row  
declare  
    
begin  
     insert into dept_history values (dept_his_seq.nextval,:old.deptno,:old.dname,:old.loc);  
end;  

 

 

恢复表中所有数据的存储过程:

create or replace procedure back_all_dept as  
cursor his_cursor is select * from dept_history;  
type his_list is table of dept_history%rowtype;  
hisl his_list;  
begin  
open his_cursor;  
fetch his_cursor bulk collect into hisl;  
close his_cursor;  
for i in hisl.first..hisl.last loop  
insert into dept values(hisl(i).deptno,hisl(i).dname,hisl(i).loc);  
dbms_output.put_line(hisl(i).deptno||' 编号的数据已经恢复');  
delete from dept_history where id=hisl(i).id;  
end loop;  
end;  

 

下面是根据条件恢复数据的存储过程:

/*此方法用于维护dept表中的数据恢复,可以根据dept_history的id来恢复, 
  也可以根据dname,deptno,loc 来恢复 格式如下: 
  exec back_dept_bydata(null,null,null,'PHOENIX'); 
  其他情况类似于.如果有多种查询条件,则只按照先后顺序进行查询,不满足条件则退出. 
*/  
create or replace procedure back_dept_bydata(  
his_id in dept_history.id%type,  
his_name in dept_history.dname%type,  
his_no in dept_history.deptno%type,  
his_loc in dept_history.loc%type  
) is  
type his_list is table of dept_history%rowtype;   
hisl his_list;  
  
procedure re_back_all(hisll in his_list) is  
back_state boolean :=false;  
begin  
if hisll.count<>0 then    
            back_state:=true;--结果集中是否有数据,如果有,则表示有更新.  
            for i in hisll.first..hisll.last loop  
                  dbms_output.put_line(hisll(i).dname||' 已经恢复完毕');  
              insert into dept values(hisll(i).deptno,hisll(i).dname,hisll(i).loc);  
             delete from dept_history where dept_history.id=hisll(i).id;  
             end loop;  
     end if;  
     if not back_state then dbms_output.put_line(' 无数据匹配'); end if;--如果没有找到数据则打印  
end;  
  
begin  
     --判断参数id是否为空值.  
    if his_id is not null then   
     select * bulk collect into hisl from dept_history where dept_history.id=his_id;  
     re_back_all(hisl);  
     --判断his_name是否为空  
     elsif his_name is not null then  
     select * bulk collect into hisl from dept_history where dept_history.dname=his_name;  
     re_back_all(hisl);  
     --判断his_no是否为空  
     elsif his_no is not null then  
     select * bulk collect into hisl from dept_history where dept_history.deptno=his_no;  
     re_back_all(hisl);  
     --判断his_loc是否为空  
     elsif his_loc is not null then  
     select * bulk collect into hisl from dept_history where dept_history.loc=his_loc;  
     re_back_all(hisl);  
       
  end if;  
end;  

欢迎大家指正.