Django

Question

我有一个模型：

class IP(models.Model):
    address     = models.GenericIPAddressField()
    fqdn        = models.CharField(max_length=255, blank=True)
    description = models.CharField(max_length=1000, blank=True)
    available   = models.BooleanField(default=True)
    reserved    = models.BooleanField(default=False)
    network     = models.ForeignKey(Network, on_delete=models.CASCADE)
    customer    = models.ForeignKey(Customer,on_delete=models.CASCADE, blank=True, null=True)

和一个表格：

class IPForm(ModelForm):
    id          = forms.CharField(widget=forms.HiddenInput())
    address     = forms.CharField(disabled=True,
                                  widget=forms.TextInput(attrs={'class':'     form-control'}))
    fqdn        = forms.CharField(widget=forms.TextInput(attrs={'class':'     form-control'}), required=False)
    description = forms.CharField(widget=forms.TextInput(attrs={'class':'     form-control ip_description'}), required = False)
    customer    = forms.ModelChoiceField(queryset=Customer.objects.all().order_by('name'), widget=forms.Select(attrs={'class':'form-control'}), required=False)
    reserved    = forms.BooleanField(widget=forms.CheckboxInput(attrs=    {'class':'checkbox'}), required=False)
    class Meta:
        model = IP
        exclude = ['available', 'network']

和一个使用 modelformset_factory:

创建表单集的视图

def ipDetailView(request, ipIDs=None):
    ipformset = modelformset_factory(IP, form=IPForm, extra=0)
    if request.method == 'POST':
        if len(request.POST.getlist('ip')):
            #we were sent a list of IP IDs to edit
            if 'clear_btn' in request.POST:
                #just remove the fqdn/description of the posted IPs
                ips = IP.objects.filter(id__in=request.POST.getlist('ip'))
                for ip in ips:
                    ip.fqdn = ''
                    ip.description = ''
                    ip.available = True
                    ip.save()
                return redirect ('iplistview', networkID=ips[0].network.id)
            else:
                #post the forms so the IPs can be edited
                formset =     ipformset(queryset=IP.objects.filter(id__in=request.POST.getlist('ip')))
                return render (request, 'ipmanager/ipdetailview.html',     {'formset' : formset})
        else:
            #we were sent a set of IP forms to commit changes for
            formset = ipformset(request.POST)
            if formset.is_valid():
                instances = formset.save()
                return redirect ('iplistview',     networkID=instances[0].network.id)
            else:
                 return render(request, 'ipmanager/ipdetailview.html',
                                                {
                                                'formset'      : formset,
                                                })

    else:
        network = IP.objects.filter(id=ipIDs)[0].network
        formset = ipformset(queryset=IP.objects.filter(id=ipIDs))
        return render (request, 'ipmanager/ipdetailview.html', {'formset' :     formset, 'network' : network})

我的问题是，无论我是提交 1 个 IP 还是 20 个 IP，我提交 IP 表单更改的 POST 部分需要 5-8 秒才能提交。代码非常简单那部分：

     formset = ipformset(request.POST)
     if formset.is_valid():
        instances = formset.save()

我什至不确定如何弄清楚为什么要花这么长时间。我没有似乎陷入其他类似问题的多对多关系。我如何着手找出导致速度缓慢的原因？

Answer 1

你可以使用django-debug-toolbar to identify what queries are taking most time, the raw SQL statement, where in your code it was called, and EXPLAIN它。

它还可以检测可以避免的潜在重复查询。

如果您注意到有重复的查询，通常可以使用 select_related.

来避免它们

Django - 在 POST 中解析表单集数据非常慢

Django - Parsing formset data in POST is painfully slow

formset