示例1,for用法：
begin
for i in 1...10000 loop
insert into test values(i,i,'aaa',sysdate);
if i mod 20 = 0 then
commit;
endif;
end loop;
commit;
end;
示例2，while用法：
declare count int default 1；
begin
while count <= 10000
loop
insert into test values(count);
set count=count+1;
end loop;
commit;
end;