Question

我有两个模型，Transaction和TransactionType。

class Transaction(models.Model):
    tran_date = models.DateField()
    tran_amount = models.FloatField(default=0.00)
    tran_payment_method = models.ForeignKey(PaymentMethod,on_delete=models.SET_NULL,null=True)
    tran_location = models.ForeignKey(Location,on_delete=models.SET_NULL,null=True)
    tran_type = models.ForeignKey(TransactionType,on_delete=models.SET_NULL,null=True)
    account = models.ForeignKey(User,on_delete=models.CASCADE,default='')
    create_date = models.DateTimeField(auto_now_add=True, blank=True)

class TransactionType(models.Model):
    name = models.CharField(max_length=200)
    status = models.IntegerField(default=1)  # 0:inactive 1:active
    income_ind=models.IntegerField(default=0) # 1: expense 2: income
    account = models.ForeignKey(User, on_delete=models.CASCADE,default='')
    create_date = models.DateTimeField(auto_now_add=True, blank=True)

我想使用ORM来运行如下查询

select b.name,sum(a.tran_amount) as total
from Transaction a
inner join TransactionType b
on a.tran_type = b.id
where a.account=some_user_id and b.income_ind=1

如何在不使用原始查询的情况下实现此目的？

Answer 1

如果TransactionType.name是唯一的（因此没有两个具有相同名称的TransactionType），那么我们可以使用.annotate(..)：

from django.db.models import Sum

TransactionType.objects.filter(
    transaction__acount_id=some_user_id
    income_ind=1
).annotate(
    total=Sum('transaction__tran_amount')
)

这将导致一个QuerySet包含TransactionType，并且每个TransactionType都将具有一个total的属性tran_amount Transaction为acount_id（要填写）的相关some_user_id。

此外，我们仅考虑TransactionType为income_ind的{{1}}个。

Django加总

1 个答案: