[英]Unable to post data to foreign key table in Django
我是Django的絕對初學者,我試圖通過將值填充到外鍵表來檢查POST方法。 我有兩張桌子。 請指導我哪里錯了。
- 包含 2 個條目的類別表,即 Coffee(PK = 1) 和 Desserts (PK = 2)
- 項目表
來自models.py:
class Category(models.Model):
cId = models.AutoField(primary_key=True)
categoryName = models.CharField(max_length=20, unique=True)
def __str__(self):
return self.categoryName
# return[self.categoryName, self.cId]
# return self.cId
class Item(models.Model):
Id = models.AutoField(primary_key=True)
itemName = models.CharField(max_length=30,unique=True)
cId = models.ForeignKey(Category,on_delete=CASCADE)
從views.py: def main(request): return render(request, "index.html")
def send(request):
if request.method == "POST":
a = request.POST.get("a");
b = request.POST.get("b");
obj = Item(itemName = a, cId =b);
obj.save()
return HttpResponse("sent")
else:
return HttpResponse("form submission failed")
從 urls.py(app):
urlpatterns = [
path('', views.main, name="main"),
path('send', views.send, name='send')
]
從 HTML:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
{% load static %}
<link rel="stylesheet" href="{% static 'css.css' %}">
<title>CHECK-POST-METHOD</title>
</head>
<body>
<div class = "container">
<form method = "post" action = "send" class = "form">
{% csrf_token %}
<label for="a">Item Name</label>
<input type="text" name="a" id="a" maxlength="30">
<label for="b">PASS FOREIGN KEY--CATEGORY ID</label>
<input type="number" name="b" id="b" maxlength="5">
<button type="submit">SUBMIT</button>
</form>
</div>
<script src="{% static 'js.js' %}"></script>
</body>
</html>
cId
需要Category
object,但您已將其指定為'1'
。 _id , so in this case cId_id
:如果要為名為foo
的ForeignKey
指定主鍵,請使用 _id
,因此在本例中cId_id
:
def send(request):
if request.method == 'POST':
a = request.POST.get('a');
b = request.POST.get('b');
obj = Item(itemName=a, cId_id=b)
obj.save()
return HttpResponse("sent")
else:
return HttpResponse("form submission failed")
正如它在錯誤中指出的那樣,Cid 必須是類別的實例所以您的視圖如下所示:
def send(request):
if request.method == "POST":
a = request.POST.get("a");
b = request.POST.get("b");
c_id = Category.objects.get(pk=b)
obj = Item(itemName=a, cId=b);
obj.save()
return HttpResponse("sent")
else:
return HttpResponse("form submission failed")
由於cId
需要是Category
類型的 object,因此您可以使用 Django 的get_object_or_404
function。 如果從cId
發布的 cId 無效,則此 function 會自動引發404
響應。
from django.shortcuts import get_object_or_404
def send(request):
if request.method == "POST":
a = request.POST.get("a");
b = request.POST.get("b");
b_obj = get_object_or_404(Category, b)
obj = Item(itemName = a, cId =b_obj)
obj.save()
return HttpResponse("sent")
else:
return HttpResponse("form submission failed")
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