oracle 循环

declare
  conNum number;
Begin
conNum :=250109107;
for item in (Select sysid from T_PROJ_DBRW Where cjrid ='system') loop
--insert into table_b(a,b,c) values (item.a,item.b,item.c);
--dbms_output.put_line('更新'|| item.sysid);

update T_PROJ_DBRW set DBBH = to_char( conNum)
Where sysid=item.sysid;

conNum :=conNum +1;
end loop;
End;