PLSQL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.