Django 查询集过滤器（可能需要子查询）

发布于 2024-09-13 12:34:39 字数 555 浏览 5 评论 0原文

我想生成一个查询集来查找不匹配项。作为一个例子，

class Vehicle(models.Model):
    car = models.CharField(max_length=100)
    model= models.CharField(max_length=100)
    passengers = models.IntegerField()

我想生成一个查询，在其中我可以找到错误地列出两种不同型号的汽车。

沿着查询的思路查找如果 car = Wrangler, model = Jeep 则查找 car = Wrangler, model 不是 Jeep 的实例。

这可以在 ORM 中完成吗？还是需要使用原始 SQL？ #django 中有人建议使用子查询，但我不熟悉如何执行此

示例输出 只是不匹配车辆的查询集（例如，一个对象存在 car = Wrangler, model = Ford，但另一个对象存在 car = Wrangler, model = Jeep）。我在想没有输入只是能够找到不匹配的地方。这还有道理吗？

原文

I want to generate a queryset to find mismatches. As an example

class Vehicle(models.Model):
    car = models.CharField(max_length=100)
    model= models.CharField(max_length=100)
    passengers = models.IntegerField()

i want to generate a query where i can find cars erroneously listed with two different models.

something along the lines of a query to find that if a car = Wrangler, model = Jeep to find instances of car = Wrangler, model is not Jeep.

Is this possible to do within the ORM, or do i need to use raw SQL? Someone in #django suggested a subquery, but I am not familiar with how to do this

Sample Output
would just be a queryset of mis-matched vehicles (for example car = Wrangler, model = Ford exists for one object but car = Wrangler, model = Jeep for another object). I was thinking of not having an input just being able to find mismatches. Does this make sense yet?

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黯然#的苍凉 2024-09-20 12:34:39

如果我理解您需要模型+汽车在一起是唯一的，那么您需要首先找到重复的记录：

from django.db.models.aggregates import Count

repetitve_cars_list = Vehicle.objects.values('car').annotate(count_car=Count('car')).filter(co
unt_car__gt=1)

这将为您提供使用多个模型定义的汽车

If I understand you need to model+car be unique together, so you need to find repetitive records first:

from django.db.models.aggregates import Count

repetitve_cars_list = Vehicle.objects.values('car').annotate(count_car=Count('car')).filter(co
unt_car__gt=1)

This will give you the cars that was defined with more than one model

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