【发布时间】：2020-09-29 16:36:44
【问题描述】：
我有以下型号：
class Village(models.Model):
packages_required = models.IntegerField()
.
.
class PackageSent(models.Model):
village = models.ForeignKey('myapp.Village')
package_count = models.IntegerField()
sending_user = models.ForeignKey('myapp.Users')
sending_account_user = models.ForeignKey('myapp.Users')
.
.
我需要选择所有 Villages 以及他们的 PackageSent 模型不仅仅是我可以分组的特定值。我构建了以下查询：
ps_query = PackageSent.objects.filter(
filter_logic
).annotate(
total_account_sent=Sum("package_count"),
sending_users=ArrayAgg("sender_user_id")
).distinct(
"sending_account_user_id"
)
Village.objects.filter(
filter_logic
).order_by(
order_by_logic
).annotate(
packages_missing=F("packages_required") - Sum("packagesent__package_count"),
users_involved=Count("packagesent__sending_account_user", distinct=True)
).prefetch_related(
models.Prefetch(
"packagesent_set",
queryset=ps_query, to_attr="packages_sent"
)
)
但是PackageSent 查询引发annotate() + distinct(fields) 未实现错误。
我需要在 MySQL 语法中查询 PackageSent 模型：
SELECT
*,
SUM(package_count) AS `total_account_sent`,
GROUP_CONCAT(sending_user) AS `sending_users`
FROM
`myapp_packagesent` ps
LEFT JOIN
`myapp_village` v ON v.id = ps.village_id
GROUP BY
`sending_account_user`,
`village_id`
ORDER BY
`total_account_sent` DESC
我想在模板中这样做：
{% for village in object_list %}
.
.
.
{% for package_sent in village.packages_sent %}
.
.
.
{% endfor %}
{% endfor %}
我怎样才能达到我想要的结果？
使用的技术：
Django 3.0
PostgreSQL
【问题讨论】：
-
嘿，你能不能把你的代码的格式改一下，这样看真的很难。
-
@IşıkKaplan 希望现在好一点。
标签： python django postgresql