请帮我从我的输出中删除重复项：
视图.py
if request.is_ajax():
subjects = Subjects.objects.distinct().order_by('-num_of_followers')[:5]
result = serializers.serialize("json", subjects)
如您所见distinct()，没有做任何事情。
我现在的输出如下所示：
aaa
aaa
aaa
bbb
ccc
但我希望它是这样的：
aaa
bbb
ccc
更新
现在我的数据库看起来像这样：
Database changed
mysql> SELECT * FROM school_subjects;
+----+----------+---------+------------+---------------------+------------------+
| id | name | user_id | created_by | created_time | num_of_followers |
+----+----------+---------+------------+---------------------+------------------+
| 1 | Math 140 | 1 | rrr | 2012-08-23 12:11:55 | 4 |
| 2 | lll | 2 | aaa | 2012-08-23 14:25:13 | 2 |
| 3 | kmkk | 2 | aaa | 2012-08-25 14:11:42 | 2 |
| 4 | llll | 2 | aaa | 2012-08-25 14:11:57 | 2 |
| 5 | Math 140 | 3 | qqq | 2012-08-25 15:29:44 | 4 |
| 6 | qweqw | 3 | qqq | 2012-08-25 15:30:32 | 1 |
| 7 | lalala | 3 | qqq | 2012-08-25 15:38:57 | 1 |
| 8 | kkdkdk | 3 | qqq | 2012-08-25 17:49:25 | 1 |
| 9 | aaaa | 2 | aaa | 2012-08-27 19:13:49 | 1 |
| 10 | mmcmcm | 2 | aaa | 2012-08-27 19:22:10 | 1 |
| 11 | aaaaa | 2 | aaa | 2012-08-27 21:17:32 | 1 |
| 12 | Math 140 | 2 | aaa | 2012-08-27 21:25:07 | 4 |
+----+----------+---------+------------+---------------------+------------------+
12 rows in set (0.00 sec)
我得到的 JSON：
[{"pk": 1, "model": "school.subjects", "fields": {"created_time": "2012-08-23 12:11:55", "num_of_followers": 4, "name": "Math 140", "created_by": "rrr", "user": 1}}, {"pk": 12, "model": "school.subjects", "fields": {"created_time": "2012-08-27 21:25:07", "num_of_followers": 4, "name": "Math 140", "created_by": "aaa", "user": 2}}, {"pk": 5, "model": "school.subjects", "fields": {"created_time": "2012-08-25 15:29:44", "num_of_followers": 4, "name": "Math 140", "created_by": "qqq", "user": 3}}, {"pk": 4, "model": "school.subjects", "fields": {"created_time": "2012-08-25 14:11:57", "num_of_followers": 2, "name": "llll", "created_by": "aaa", "user": 2}}, {"pk": 3, "model": "school.subjects", "fields": {"created_time": "2012-08-25 14:11:42", "num_of_followers": 2, "name": "kmkk", "created_by": "aaa", "user": 2}}]
从这个例子你可以看到我得到了 Math 140 3 次，但我希望它只出现一次。
谢谢你。