Question

我有一个名为share的表，如下所示：

+----+----------+----------+----------------+----------------------------------+
| id | users_id | files_id | shared_user_id | shared_date                      |
+----+----------+----------+----------------+----------------------------------+
|  2 |        1 |        2 |              2 | 2013-03-13 20:33:36.766030+00:00 |
|  4 |        1 |        4 |              2 | 2013-03-13 20:33:36.766030+00:00 |
|  5 |        1 |        5 |              2 | 2013-03-13 20:33:36.766030+00:00 |
|  6 |        1 |        6 |              2 | 2013-03-13 20:33:36.766030+00:00 |
|  8 |        1 |        2 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 10 |        1 |        4 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 11 |        1 |        5 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 12 |        1 |        6 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 13 |        1 |        7 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 14 |        1 |        8 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 15 |        1 |        9 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 16 |        1 |       12 |              2 | 2013-03-14 16:15:29.580095+00:00 |
| 18 |        1 |        2 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 20 |        1 |        4 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 21 |        1 |        5 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 22 |        1 |        6 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 23 |        1 |        7 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 24 |        1 |        8 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 25 |        1 |        9 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 26 |        1 |       12 |              2 | 2013-03-14 16:17:57.929392+00:00 |
| 27 |        1 |       12 |              2 | 2013-03-15 15:51:50.344222+00:00 |
| 28 |        1 |        9 |              3 | 2013-03-15 15:58:06.655270+00:00 |
| 29 |        1 |        2 |              2 | 2013-03-15 15:59:58.023322+00:00 |
+----+----------+----------+----------------+----------------------------------+

我想找出每个files_id共享文件的用户总数。我怎么能这样做？

试过这个：

Share.objects.filter(users_id=request.user.id).values_list('shared_user_id', flat=True).distinct()

但这只计算shared_user_id。

以下是我的模特：

class Share(models.Model):
    users = models.ForeignKey(User)
    files = models.ForeignKey(File)
    shared_user_id = models.IntegerField()
    shared_date = models.TextField()

class File(models.Model):
    users = models.ForeignKey(User)
    file_name = models.CharField(max_length=100)
    type = models.CharField(max_length=10)
    source = models.CharField(max_length=100)
    start_date = models.TextField()
    time_overview = models.CharField(max_length=55)
    end_date = models.TextField()
    duration = models.TextField()
    size_overview = models.IntegerField()
    size = models.TextField()
    flag = models.TextField()
    flag_r = models.TextField()

Answer 1

您想使用Django的Aggregate功能。

使用您的模型，您可以：

counts = Share.objects.all().annotate(num_shares=Count("shared_user_id"))
for count in counts:
    print "%s - %s shares" % (count.files, count.num_shares)

要获取特定文件的计数，假设file是表示给定文件的对象：

count = Share.objects.filter(files=file).annotate(num_shares=Count("shared_user_id"))
print count[0].num_count

Answer 2

您可以使用简单查询来计算mysql

SELECT
    files_id,
    count(shared_user_id) AS `Shared`
FROM mytable
GROUP BY files_id
ORDER BY files_id

在django中计算给定文件的共享用户数？

2 个答案: