mysql 查询表中 字段没重复值的数据

mysql 查询表中 字段没有重复值的数据
比如说 有个表
id title time
1 a 20120304
2 a 20121314
3 b 20121314
4 c 20121111
5 d 20121221
6 c 20121111
 
第一种想要的结果：
想查出title没有重复的数据 有没有办法
想要结果 为
id title time
3 b 20121314
5 d 20121221

第二种想要的结果
第一种多加个条件，如果title相同 但是time也相同 那也显示出这条数据(仅一条)
id title time
3 b 20121314
4 c 20121111
5 d 20121221

大家有没有好的办法

[解决办法]

SQL code

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)
[解决办法]
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)
[解决办法]
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)))