每500条记录commit;
sqlplus -s $USER/$PWD@DBNAME <<!!
declare
lcnt number:=0
begin
select count(1) into lcnt from tbsutdent where status='1';
for i in 0..ceil(lcnt/500)+1 loop
update tbstudent set status='0' where status='1' and rownum<=500;
commit;
end loop;
!!