在Django視圖中，如何更改類成員的值？

Question

我想增加候選人的賺取價值，如果他得票。所以我在result_view中寫了這部分，但它不起作用。

這是我的看法。

---

from django.shortcuts import render_to_response 

from election.models import * 

# /candidate/ view 
def candidate_view(request): 
    if request.method == 'GET': 
     c = Candidate.objects.all() 
     return render_to_response('candidate.html', {'candidates': c}) 

# /candidate/result/ view 
def result_view(request): 
    if request.method == 'POST': 
     c = Candidate.objects.all() 
     ec = Candidate.objects.filter(num=request.POST.get('choice')) 

     ec[0].earn += 1 
     ec[0].name = 'semi kwon' 
     ec[0].save() 

     #return render_to_response('result.html', {'candidates': ec}) 
     return render_to_response('result.html', {'candidates': c}) 

---

這是我的模型。

---

from django.db import models 


class Candidate(models.Model): 

    num = models.IntegerField() 
    name = models.TextField() 
    major = models.TextField() 
    grade = models.IntegerField() 
    earn = models.IntegerField(default = 0, blank=True, editable=True) 

    def __unicode__(self): 
     return "%d : %s"%(self.num, self.name,) 

---

我怎樣才能解決這個問題？

Answer 1

更新候選人後是否檢查了數據庫？

由於您在更新候選人（ec）之前獲得候選人（c），您可能已更新候選人，但已將舊套餐傳遞給模板。

這將是更好的使用的一種形式，但爲了保持你的邏輯，試試這個：

def result_view(request): 
    # csrf update etc 
    # your request.method GET here 
    # ... 
    if request.method == 'POST': 
     # dictionary with vars that will be passed to the view 
     params = {} 

     # check if there is a candidate with this num 
     # before you do anything with it 
     # you could do a try/except instead 
     if Candidate.objects.filter(num=request.POST.get('choice')).count(): 
      # Getting candidate 
      candidate = Candidate.objects.get(num=request.POST.get('choice')) 
      # Updating candidate 
      candidate.earn += 1 
      # I don't know what this is, but let's keep it 
      candidate.name = 'semi known' 
      # Saving candidate 
      candidate.save() 

     else: 
      # returning error, candidate not found 
      params['error'] = "No candidate with this num" 

     # updating candidates list 
     params['candidates'] = Candidate.objects.all() 

     # rendering view 
     return render_to_response('result.html', params)