root@localhost : test 04:59:19>select * from tes;
+------+-------+----------+
| id   | title | time     |
+------+-------+----------+
|    1 | a     | 20120304 |
|    2 | a     | 20121314 |
|    3 | b     | 20121314 |
|    4 | c     | 20121111 |
|    5 | d     | 20121221 |
|    6 | c     | 20121111 |
+------+-------+----------+
6 rows in set (0.00 sec)

root@localhost : test 04:59:22>select a.* from tes a,(select title,count(*) from tes group by title having count(*)=1) b where a.title=b.title;
+------+-------+----------+
| id   | title | time     |
+------+-------+----------+
|    3 | b     | 20121314 |
|    5 | d     | 20121221 |
+------+-------+----------+
2 rows in set (0.00 sec)

root@localhost : test 04:59:47>select id,title,time from tes group by title,time;
+------+-------+----------+
| id   | title | time     |
+------+-------+----------+
|    1 | a     | 20120304 |
|    2 | a     | 20121314 |
|    3 | b     | 20121314 |
|    4 | c     | 20121111 |
|    5 | d     | 20121221 |
+------+-------+----------+
5 rows in set (0.00 sec)

------解决方案--------------------

这类问题似乎此版很多，你不妨搜索下

SQL code
mysql> select * from tb;
+----+-------+----------+
| id | title | time     |
+----+-------+----------+
|  1 | a     | 20120304 |
|  2 | a     | 20121314 |
|  3 | b     | 20121314 |
|  4 | c     | 20121111 |
|  5 | d     | 20121221 |
|  6 | c     | 20121111 |
+----+-------+----------+
6 rows in set (0.00 sec)

mysql> select * from tb a where not exists(select id from tb b where b.title=a.title and b.id<>a.id);
+----+-------+----------+
| id | title | time     |
+----+-------+----------+
|  3 | b     | 20121314 |
|  5 | d     | 20121221 |
+----+-------+----------+
2 rows in set (0.00 sec)

mysql> select * from tb a where not exists(select id from tb b where b.title=a.title and b.id<>a.id and b.time<>a.time) group by a.title;
+----+-------+----------+
| id | title | time     |
+----+-------+----------+
|  3 | b     | 20121314 |
|  4 | c     | 20121111 |
|  5 | d     | 20121221 |
+----+-------+----------+
3 rows in set (0.00 sec)

------解决方案--------------------
1
select * from tt a where not exists(select 1 from tt where a.title=title and a.id<>id)
2



select * from tt a where exists(select 1 from tt where a.title=title and a.time=time and a.id<id)
union  
select * from tt a where not exists(select 1 from tt where ((a.title=title and a.id<>id)
or
(a.title=title and a.time=time and a.id<id)))