python - Django 将所有具有不同外键 ID 的值求和，并使用相关表中的字段将它们压缩

Question

我想执行类似于 this 的操作(即在付款表中获取不同事件金额的总和，然后按事件详细信息和为他们支付的总金额对付款进行分组。还可以获取用户以及他们为事件支付的费用)在 Django 中使用 PostgreSQL。

我的模型如下:

class UserProfile(User):
    onames = models.CharField(max_length=30, blank=True)
    phoneNumber = models.CharField(max_length=15, blank=True)
    regNo = models.CharField(max_length=15)
    designation = models.CharField(max_length=3,choices=DESIGNATION_CHOICES, default='MEM')
    image = models.ImageField(max_length=100,upload_to='photos/%Y/%m/%d', blank=True, null=True, default='photos/2010/03/placeholder.jpg')
    course = models.CharField(max_length=30, blank=True, null=True)
    timezone = models.CharField(max_length=50, default='Africa/Nairobi')
    smsCom = models.BooleanField()
    mailCom = models.BooleanField()

class Payments(models.Model):
    username = models.ForeignKey(UserProfile, related_name='payer')
    receiptNo = models.CharField(max_length=30, primary_key=True)
    particulars = models.CharField(max_length=50)
    date = models.DateField(auto_now_add=True)
    amount = models.FloatField(max_length=99, blank=True)
    eventID = models.ForeignKey('events', null=True, blank=True)
    receiver = models.ForeignKey(UserProfile, related_name='receiver')
    deleted = models.BooleanField()

class events(models.Model):
    eventName  = models.CharField(max_length=100)
    eventID =  models.AutoField(primary_key=True)
    details = models.TextField()
    attendanceFee = models.FloatField(max_length=99)
    date = models.DateField()
    username = models.ManyToManyField(UserProfile, related_name='user')
    eventposter = models.ForeignKey(UserProfile, related_name='event_poster')
    deleted = models.BooleanField()

Answer 1

经过一些神经破解之后，解决方案是将查询拆分为 2 个，即一个用于分组和求和，另一个用于获取匹配值。

关于分组和求和，引用here