mysql> select * from test;
+----+------+--------------+------------+
| id | cid  | title        | pubdate    |
+----+------+--------------+------------+
|  1 |    1 | 测试通知新闻 | 2011-12-05 |
|  2 |    2 | 测试通知新闻 | 2011-12-05 |
|  3 |    3 | 测试通知新闻 | 2011-12-04 |
|  4 |    1 | 测试新闻1    | 2011-12-04 |
|  5 |    2 | 测试新闻2    | 2011-12-04 |
|  6 |    3 | 测试新闻3    | 2011-12-03 |
|  7 |    4 | 测试新闻4    | 2011-12-02 |
|  8 |    2 | 测试新闻5    | 2011-12-02 |
|  9 |    1 | 测试新闻6    | 2011-12-02 |
| 10 |    2 | 测试新闻7    | 2011-12-01 |
| 11 |    3 | 测试通知新闻 | 2011-12-01 |
| 12 |    2 | 测试通知新闻 | 2011-11-30 |
| 13 |    3 | 测试新闻9    | 2011-11-30 |
| 14 |    1 | 测试新闻10   | 2011-11-30 |
| 15 |    4 | 测试新闻12   | 2011-11-28 |
| 16 |    2 | 测试通知新闻 | 2011-11-27 |
+----+------+--------------+------------+
16 rows in set (0.01 sec)

mysql> select *
    -> from test a
    -> where cid in (1,2,3)
    -> and not exists (
    ->  select 1 from test
    ->  where id<a.id and title=a.title
    ->  and pubdate between a.pubdate-interval 2 day and a.pubdate+interval 2 day
    ->  );
+----+------+--------------+------------+
| id | cid  | title        | pubdate    |
+----+------+--------------+------------+
|  1 |    1 | 测试通知新闻 | 2011-12-05 |
|  4 |    1 | 测试新闻1    | 2011-12-04 |
|  5 |    2 | 测试新闻2    | 2011-12-04 |
|  6 |    3 | 测试新闻3    | 2011-12-03 |
|  8 |    2 | 测试新闻5    | 2011-12-02 |
|  9 |    1 | 测试新闻6    | 2011-12-02 |
| 10 |    2 | 测试新闻7    | 2011-12-01 |
| 11 |    3 | 测试通知新闻 | 2011-12-01 |
| 13 |    3 | 测试新闻9    | 2011-11-30 |
| 14 |    1 | 测试新闻10   | 2011-11-30 |
| 16 |    2 | 测试通知新闻 | 2011-11-27 |
+----+------+--------------+------------+
11 rows in set (0.00 sec)

mysql>