Django 外键连接

Question

我有一个模型 Field，它与 TreeSensor 和 WeatherStation 模型有 OneToMany 连接。我试图传递每个 treesensor/weatherstation 模型的查询，这些模型与每个不同字段的 id 相匹配，但得到一个 Field 'id' expected a number but got <built-in function id>. 。我该如何解决这个问题？也许在 filter 上更改一些内容？

class Field(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE, blank=True, null=True, default=None)
    friendly_name = models.CharField(max_length=24, blank=True)
    soil_type = models.CharField(max_length=24, choices=SOIL_TYPES, blank=True)  
    cultivation = models.CharField(max_length=128, choices=CULTIVATIONS, blank=True)  
    kml = models.FileField(upload_to = user_directory_path_kml, null=True, blank=True)

class TreeSensor(models.Model):  
    field = models.ForeignKey(Field, on_delete=models.CASCADE)
    ...

class WeatherStation(models.Model):
    field = models.ForeignKey(Field, on_delete=models.CASCADE)
    ...

查看

def map(request):
    field_list = models.Field.objects.filter(user = request.user)
    tree_sensors = models.TreeSensor.objects.filter(field__pk = id)
    weather_stations = models.WeatherStation.objects.filter(field__pk = id)
    context = {
        "title": "Map",
        "field_list": field_list,
        "tree_sensors": tree_sensors,
        "weather_stations" : weather_stations,
    }
    template = 'agriculture/map.html'
    return render(request, template, context)

Answer 1

根据您的观点，您正在过滤某些由 id 命名的字段 field，此处未定义....

你有一个字段查询集，所以你可能应该这样做：

def map(request):
    field_list = models.Field.objects.filter(user = request.user).values_list('id', flat=True)
    tree_sensors = models.TreeSensor.objects.filter(field__id__in = field_list)
    weather_stations = models.WeatherStation.objects.filter(field__id__in = field_list)

Answer 2

@Walucas 你的方法是正确的，但有点不同。结果是这样的：查看

def map(request):

    field_list = models.Field.objects.filter(user = request.user)
    tree_sensors = models.TreeSensor.objects.filter(field_id__in = field_list.values_list('id',flat=True))
    weather_stations = models.WeatherStation.objects.filter(field_id__in = field_list.values_list('id',flat=True))
    context = {
        "title": "Map",
        "field_list": field_list,
        "tree_sensors": tree_sensors,
        "weather_stations" : weather_stations,
    }
    template = 'agriculture/map.html'
    return render(request, template, context)

Django 外键连接

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