查询求解,该怎么处理

查询求解
create table t_test
(
  t_num varchar(30),
  t_time varchar(30),
  t_other varchar(30)
)
insert into t_test values('1001','20120701','aaaaaaaaaaaa');
insert into t_test values('1001','20120707','bbbbbbbbbbbb');
insert into t_test values('1002','20120702','cccccccccccc');
insert into t_test values('1003','20120706','dddddddddddd');
insert into t_test values('1003','20120709','eeeeeeeeeeee');


如何查询出1001,1002,1003这三个账号的时间最新的信息

[解决办法]

SQL code

select * from t_test twhere not exists(select 1 from t_test where t_time>t.t_time and t_num=t.t_num)
[解决办法]
SQL code
select * from t_test twhere not exists(select 1 from t_test where t_time>t.t_time and t_num=t.t_num)--或者select * from t_test twhere t_time=(select max(t_time) from t_test where t_num=t.t_num)