oracle 存储过程 条件表复制

Create or replace procedure MoveDataFromAToB
  is
     --定义变量--
     p_braid  varchar2(40);
     p_merid  varchar2(40);
    
     --定义指针--
     cursor cur_data_AAA
     is
       select braid, merid from aaa_test;
begin
     --遍历指针游标
     for rec_data_AAA in cur_data_AAA
        loop
           --初始化变量--
           p_braid :=null;
           p_merid :=null;
            begin
                --当目的表中存在该主键时，将游标的值赋给变量--
                select  braid, merid
                   into p_braid,p_merid
                   from bbb_test            
                where braid=rec_data_AAA.braid;
               exception
                   when others then
                      --异常处理，说明目标表中没有该主键，将变量初始化为空值--
                                 p_braid :=null;
                                 p_merid :=null;
            end;
           --当目标表中存在该主键时，暂时做标记处理--
           if p_braid is not null then
               if rec_data_AAA.merid=p_merid then
                  update aaa_test
                       set aaa_test.payid='U'
                   where aaa_test.p_braid=rec_data_AAA.p_braid;
               else
                  update bbb_test
                       set bbb_test.merid=rec_data_AAA.merid
                   where aaa_test.braid=rec_data_AAA.p_braid;
               
               end if;
          --当目的表中不存在该主键时，进行插入--
          else
               insert into bbb_test(braid, merid) values(rec_data_AAA.braid,rec_data_AAA.merid);
               update aaa_test
                       set aaa_test.payid='N'
                   where aaa_test.braid=rec_data_AAA.p_braid;
          end if;  
         commit ;
        end loop;
 
exception
   when others then
      rollback;
end MoveDataFromAToB;