如何将查询集添加到多对多关系？

Question

我有以下型号：

class EnMovielist(models.Model):
    content_ID = models.CharField(max_length=30)
    release_date = models.CharField(max_length=30)
    running_time = models.CharField(max_length=10)
    actress = models.CharField(max_length=300)
    series = models.CharField(max_length=30)
    studio = models.CharField(max_length=30, null=True)
    director = models.CharField(max_length=30)

    def __str__(self):
        return self.content_ID


class EnActress(models.Model):
    name = models.CharField(max_length=100, null=True)
    movielist = models.ManyToManyField(EnMovielist, related_name='movies')

    def __str__(self):
        return self.name

我在 Django 中尝试这样做时出错 shell,

b = EnActress.objects.values_list('name', flat=True)
a = EnMovielist.objects.filter(actress__contains=b).values_list('content_ID')

b.movielist.add(a)



AttributeError: 'QuerySet' object has no attribute 'movielist'

如何将 django 查询集添加到多对多字段中？我不知道为什么会这样。任何帮助表示赞赏！ :)

Answer 1

您应该从实例调用 m2m add 并且添加实体也应该是模型实例。否则你的表达没有意义。

b = EnActress.objects.get(pk=some_pk) # get an instance, not queryset
a = EnMovielist.objects.get(pk=some_pk) # also instance
b.movielist.add(a)

Answer 2

如果您打算以后 add 建立新关系，则不应使用 values_list。来自 docs:

values() and values_list() are both intended as optimizations for a specific use case: retrieving a subset of data without the overhead of creating a model instance

[强调我的]

如果没有很好地描述你想要实现的目标，就很难说出你在做什么。

如何将查询集添加到多对多关系？

How to add queryset to ManyToMany relationship?

python

django

manytomanyfield

django-queryset