truncate_insert_ok.txt

orale培训教材包括了所有的sql说明和实例

--一个 显示truncate(截断表)功能的例子，用tochar显示执行时间

----建立表
set serveroutput on
drop table person;
create table person (id number(10),name varchar2(20));
--------------------------------------------------

--data insert
declare
n_loop number;
s_time date;
--s_time varchar2;
e_time date;
begin
  select sysdate into s_time from dual ;
  for n_loop in 1..100000 loop
	insert into person values(n_loop,'name'||n_loop);
	commit;
  end loop;
  select sysdate into e_time from dual ;
  dbms_output.put_line(to_char((e_time),'hh:mi:ss'));
  dbms_output.put_line(to_char((s_time),'hh:mi:ss'));
end;



-------------------------------------------------
--使用delete.sql脚本代替此段程序
--使用delete ,commit
declare
s_time date;
--s_time varchar2;
e_time date;
v_name varchar2(13);
begin
  --select to_char(sysdate,'yyyy/mm/dd hh:mi:ss) into s_time from dual ;
  select sysdate into s_time from dual ;
  delete from person;
  commit;
  select sysdate into e_time from dual ;
  
dbms_output.put_line(to_char((e_time),'hh:mi:ss'));
dbms_output.put_line(to_char((s_time),'hh:mi:ss'));

end;

-------------------------------------------------

--truncate;
@truncate

select to_char(sysdate,'hh24:mi:ss') from dual;
delete from person;
commit;
select to_char(sysdate,'hh24:mi:ss') from dual;

---
TO_CHAR(
--------
21:39:42


已删除100000行。


提交完成。


TO_CHAR(
--------
21:42:35