Question

我正在回到FormSet。 Django调试工具栏向我展示了对于is_valid（）和save（），查询集中的每个模型都被重新查询，即使它们在构造FormSet期间已经从数据库中检索到了所有模型。这里没有特殊的对象关联。

E.g。用户有5个域。这将发出1 + 5 + 5个查询== 11个查询。如何消除最后10个查询？

版本：

Python 2.7.5
Django 1.6.1

models.py

class Domain(Model):
    name = models.CharField(unique=True, max_length=255)
    user = models.ForeignKey(User)

    class Meta:
        db_table = 'domain'

forms.py

class DomainForm(ModelForm):
    class Meta:
        model = Domain

DomainFormSet = modelformset_factory(Domain, form=DomainForm, extra=0)

class DomainFormSetWithQuerySet(DomainFormSet):
    def __init__(self, user, data=None):
        super(DomainFormSetWithQuerySet, self).__init__(data, prefix='domains', queryset=Domain.objects.filter(user=user))

views.py

def view(request):
    if request.method == 'POST':

        domain_formset = DomainFormSetWithQuerySet(request.user, request.POST)

        // One big select query:
        // select * from domains where user_id = ? order by id asc
        //
        // Then, an additional select query for each form in the formset:
        // select * from domains where domain_id = ?
        if domain_formset.is_valid():

            // An additional select query for each form in the formset:
            // select * from domains where domain_id = ?
            domain_formset.save()

Django FormSets：如何消除对is_valid（）和save（）的额外查询？

0 个答案: