找不到页面 (404) 没有符合给定查询的购物车
Page not found (404) No cart matches the given query
出现错误：
Page not found (404) No cart matches the given query.
Request Method: GET Request
URL: http://127.0.0.1:8000/change_quan?cid=1&quantity=2
Raised by: myapp.views.change_quan
当我试图在数据库中保存数量值时
我试过了，但这个错误总是出现
我的views.py
def productcart(request):
context = {}
items = cart.objects.filter(user__id=request.user.id,status=False)
context["items"] = items
if request.user.is_authenticated:
if request.method=="POST":
pid = request.POST["pid"]
qty = request.POST["qty"]
img = request.POST["img"]
dis_price = request.POST["dis_price"]
is_exist = cart.objects.filter(product__id=pid,user__id=request.user.id,status=False)
if len(is_exist)>0:
context["msg"] = "item already exist in cart"
context["cls"] = "alert alert-warning"
else:
product = get_object_or_404(Product,id=pid)
usr = get_object_or_404(User,id=request.user.id)
c = cart(user=usr,product=product,quantity=qty,image=img,total_price=dis_price)
c.save()
context["msg"] = "{} Added in cart".format(product.name)
context["cls"] = "alert alert-success"
else:
context["status"] = "Please login first to add products to cart"
return render(request,'E-commerce-cart.html',context)
def get_cart_data(request):
items = cart.objects.filter(user__id=request.user.id,status=False)
sale,total,quantity=0,0,0
for i in items:
sale+=i.product.discount
total+=i.product.price
quantity+=i.quantity
res={
"total":total,"offer":sale,"quan":quantity
}
return JsonResponse(res)
def change_quan(request):
qty = request.GET["quantity"]
cid = request.GET["cid"]
print(request.GET)
cart_obj = get_object_or_404(cart,id=cid)
cart_obj.quantity = qty
cart_obj.save()
return HttpResponse(1)
我的urls.py
"""emarket URL Configuration
The `urlpatterns` list routes URLs to views. For more information please see:
https://docs.djangoproject.com/en/3.2/topics/http/urls/
Examples:
Function views
1. Add an import: from my_app import views
2. Add a URL to urlpatterns: path('', views.home, name='home')
Class-based views
1. Add an import: from other_app.views import Home
2. Add a URL to urlpatterns: path('', Home.as_view(), name='home')
Including another URLconf
1. Import the include() function: from django.urls import include, path
2. Add a URL to urlpatterns: path('blog/', include('blog.urls'))
"""
from os import name
from django.contrib import admin
from django.urls import path
from myapp import views
from django.conf.urls.static import static
from django.conf import settings
urlpatterns = [
path('admin/', admin.site.urls),
path('',views.home,name='home'),
path('shop/',views.shop,name='shop'),
path('login/',views.create_user,name='login'),
path('logout/',views.user_logout,name='logout'),
path('cart/',views.productcart,name='cart'),
path('checkout/',views.checkout,name='checkout'),
path('product_detail/',views.product_detail,name='prodct-detail'),
path('find_us/',views.find_us,name='find'),
path('blog/',views.blog,name='blog'),
path('base/',views.base),
path('api/categories',views.all_categories,name="all_categories"),
path('api/brand',views.brand,name="brand"),
path('api/products',views.product_filter_api,name="product_filter_api"),
path('user_check/',views.check_user,name="check_user"),
path('filter_product/',views.filter_product,name="filter_product"),
path('add_to_favourite/',views.add_to_favourite,name="add_to_favourite"),
path('all_favourites/',views.all_favourites,name="all_favourites"),
path('forgotpass',views.forgotpass,name="forgotpass"),
path('resetpass',views.resetpass,name="resetpass"),
path('get_cart_data',views.get_cart_data,name="get_cart_data"),
path('change_quan',views.change_quan,name='change_quan'),
]+static(settings.MEDIA_URL,document_root=settings.MEDIA_ROOT)
我的models.py
class cart(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
product = models.ForeignKey(Product,on_delete=models.CASCADE)
image = models.ImageField(default=False)
total_price=models.FloatField(default=False)
quantity = models.IntegerField()
status = models.BooleanField(default=False)
added_on = models.DateTimeField(auto_now_add=True)
updated_on = models.DateTimeField(auto_now=True)
def __str__(self):
return self.user.username
我的html代码
{% extends 'base.html' %}
{% block head %}
<style>
.k{height: 1px;background-color: rgb(211, 207, 207);}
.s{color:rgb(240, 240, 240);
letter-spacing: 3px;
font-family:-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
font-weight: 400;}
.cncl_icn{
float: left;
margin: 15px;
padding-top: 10px;
}
.a:hover{
background-color:rgba(152, 209, 255, 0.705);color: rgb(255, 255, 255);box-shadow:0px 0px 7px 7px rgba(204, 201, 201, 0.5) ;
}
@media screen and (max-width:680px){
.b{opacity: 0;}
/* .v{position: absolute;top: 5px;} */
.s{font-size: 15px;}
}
@media screen and (min-width:1024px){
.s{font-size: 20px;}
}
</style>
{% endblock %}
{% block body %}
{% if user.is_superuser %}
<div class="container-fluid "></div>
<h1 class="jumbotron my-5" >you are not Allowed here</h1>
{% else %}
{% if status %}
<h1 class="jumbotron my-5">{{status}}</h1>
{% else %}
{% if msg %}
<div class="{{cls}}">{{msg}}</div>
{% endif %}
<div class="row v " style="margin-right: 0%;">
<div class="col-lg-7" >
<div class="row text-center p-3 b" style="background-color: rgba(2, 184, 184, 0.863); background-attachment: fixed;">
<div class="col-md-3 "> <h3 class="s">Product</h3></div>
<div class="col-md-3 "><h3 class="s">Price</h3></div>
<div class="col-md-3 "><h3 class="s">Qantity</h3></div>
<div class="col-md-3 "><h3 class="s">Total</h3></div>
</div>
{% for i in items %}
<div class="row a border-bottom" id="col{{i.product.id}}">
<div class="col-md-3 text-center " >
<i class="far fa-times-circle cncl_icn" id="cross{{i.product.id}}" style="font-size: 30px;"></i>
<img class="mt-4" src="/media/{{i.image}}" alt="check ur internet!" height="150px">
<a href="/product_detail/?id={{i.product.id}}" style="text-decoration: none;"><h4 class="ml-5" style="color: black;">{{i.product.name}}</h4></a>
<p class="ml-5">Size:{{i.product.size}} , color:{{i.product.color}}</p>
</div>
<div class="col-md-3 text-center mt-5">
{%if i.total_price < i.product.price%}
<del style="font-weight: bold; color: grey;" >${{i.product.price}}</del> $<p class="d-inline" style="font-weight: bold;" id="price{{i.product.id}}">{{i.total_price}}</p>
{% else %}
$<p class="d-inline" style="font-weight: bold;" id="price{{i.product.id}}">{{i.product.price}}</p>
{% endif %}
</div>
<div class="col-md-3 text-center">
<div class="form-group mt-4">
<div class="input-group">
<div class="input-group-btn ">
<button id="down" class="btn btn-default" onclick="change_quan('{{i.product.id}}','minus')" style="font-size: 25px;background: none;border: none;font-weight: bold;">-</button>
</div>
<input type="number" id="cart{{i.product.id}}" class="form-control text-center pt-3" value="{{i.quantity}}" style="width: 30px;border: none;font-weight: bold;background: none;">
<div class="input-group-btn">
<button id="up" class="btn btn-default" onclick="change_quan('{{i.product.id}}','plus')" style="font-size: 25px;background: none;border: none;font-weight: bold;">+</button>
</div>
</div>
</div>
</div>
<div class="col-md-3 mt-5 text-center">
{%if i.total_price < i.product.price %}
$<p class="d-inline" style="font-weight: bold;" id="total{{i.product.id}}">{{i.total_price}}</p>
{% else %}
$<p class="d-inline" style="font-weight: bold;" id="total{{i.product.id}}">{{i.product.price}}</p>
{% endif %}
</div>
</div>
<script>
$(function() {
$("#cross{{i.product.id}}").hover(function() {
$("#cross{{i.product.id}}").toggleClass("fas fa-times-circle").toggleClass("far fa-times-circle")
})
// to remove product from cart
$("#cross{{i.product.id}}").confirm({
title: 'Confirm',
content: 'Are you sure to remove this product from cart',
theme: 'modern',
buttons:{
confirm: function() {
$('#col{{i.product.id}}').remove()
},
cancel: function (){}
}
})
})
</script>
{% endfor %}
</div>
<script>
function grandTotal(){
$.ajax({
url:"{% url 'get_cart_data' %}",
type:'get',
success:function(data){
p = Math.round((data.offer/data.total)*100,2)
$('.item_total').html("$"+data.total)
$('#offer').html("$"+data.offer)
$('#per').html("("+p+"%)")
$('#quantity').html(data.quan)
c = (data.total)-(data.offer)
$('#grand_Total').html("$"+c)
}
})
}
grandTotal()
function change_quan(id,action){
let old = $("#cart"+id).val();
quan = 0
if(action=="plus"){
quan+=parseInt(old)+1
$('#total'+id).text( parseFloat($('#total'+id).text()) + parseFloat($('#price'+id).text()))
}
else{
quan+=parseInt(old)-1
$('#total'+id).text( parseFloat($('#total'+id).text()) - parseFloat($('#price'+id).text()))
}
$("#cart"+id).val(quan);
$.ajax({
url:"{% url 'change_quan' %}",
type:"get",
data:{cid:id,quantity:quan},
success:function(data){
alert(data)
}
});
}
</script>
<div class="col-md-5 text-center py-5" style="background-color: rgba(255, 176, 218, 0.397);">
<div id="cartt"></div>
<div class="row">
<img src="/static/Images/estore1.png" alt="" height="300px" style="margin: auto;">
</div>
<div class="pb-3 " style="font-size:30px;font-weight: bold;">--------------------</div>
<h4 class="pt-3" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">Total: <span style="font-size: 28px;" class="item_total"></span></h4>
<h4 class="pt-1" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">Quantity: <span style="font-size: 28px;" id="quantity"></span><span style="text-transform: none;"> Items</span></h4>
<h4 class="pt-1" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">You Saved: <span style="font-size: 28px;" id="offer"></span><span class='text-success'style="font-size: 20px;" id="per"></span></h4>
<h4 class="py-1" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">Grand Total: <del style="font-size: 25px; color:grey;" class="item_total"></del><span style="font-size: 28px;" id="grand_Total"></span></h4>
<h4 class="pt-3">Shipping charges will calculated at checkout</h4>
<form class="pt-3" action="" >
<!-- <input type="text" placeholder="Coupon code.." name="cod" class="mt-3 text-center" style="letter-spacing: 2px;font-size: 20px;border-radius: 25px;width: 250px;height: 47px;background-color: rgb(255, 255, 255);border:2px solid thistle;" >
<input type="submit" class="mt-3" value="Apply Code"name="acd" style="letter-spacing: 2px;font-size: 25px;border-radius: 25px;border: none;width: 250px;height: 45px;background-color: rgb(161, 158, 158);color: rgb(255, 255, 255);" > -->
<input type="submit" value="CHECKOUT" name="che" class="mt-5" style="letter-spacing: 2px;font-size: 25px;border-radius: 25px;border: none;width: 250px;height: 45px;background-color: black;color: rgb(255, 255, 255);" >
</form>
</div>
</div>
{% endif %}
</div>
{% endif %}
{% endblock %}
如果数据不存在'get_object_or_404' 将抛出 404 错误，根据您的要求您正在尝试使用主键 1 检索数据，但数据不可用
这就是您收到此错误的原因。所以请检查你 table 或尝试使用其他 pk 值
def change_quan(request):
qty = request.GET["quantity"]
cid = request.GET["cid"]
print(request.GET)
cart_obj = get_object_or_404(cart,id=cid) # please check this cid value
cart_obj.quantity = qty
cart_obj.save()
return HttpResponse(1)
get_object_or_404 在这里不是正确的选择。由于在数据库中找不到带有 id=cid 的对象，因此引发了 404 错误。这是 get_object_or_404.
的预期行为
您是否打算使用 get_or_create 对象以防找不到试图从数据库中获取的对象？
出现错误：
Page not found (404) No cart matches the given query. Request Method: GET Request URL: http://127.0.0.1:8000/change_quan?cid=1&quantity=2 Raised by: myapp.views.change_quan
当我试图在数据库中保存数量值时 我试过了，但这个错误总是出现
我的views.py
def productcart(request):
context = {}
items = cart.objects.filter(user__id=request.user.id,status=False)
context["items"] = items
if request.user.is_authenticated:
if request.method=="POST":
pid = request.POST["pid"]
qty = request.POST["qty"]
img = request.POST["img"]
dis_price = request.POST["dis_price"]
is_exist = cart.objects.filter(product__id=pid,user__id=request.user.id,status=False)
if len(is_exist)>0:
context["msg"] = "item already exist in cart"
context["cls"] = "alert alert-warning"
else:
product = get_object_or_404(Product,id=pid)
usr = get_object_or_404(User,id=request.user.id)
c = cart(user=usr,product=product,quantity=qty,image=img,total_price=dis_price)
c.save()
context["msg"] = "{} Added in cart".format(product.name)
context["cls"] = "alert alert-success"
else:
context["status"] = "Please login first to add products to cart"
return render(request,'E-commerce-cart.html',context)
def get_cart_data(request):
items = cart.objects.filter(user__id=request.user.id,status=False)
sale,total,quantity=0,0,0
for i in items:
sale+=i.product.discount
total+=i.product.price
quantity+=i.quantity
res={
"total":total,"offer":sale,"quan":quantity
}
return JsonResponse(res)
def change_quan(request):
qty = request.GET["quantity"]
cid = request.GET["cid"]
print(request.GET)
cart_obj = get_object_or_404(cart,id=cid)
cart_obj.quantity = qty
cart_obj.save()
return HttpResponse(1)
我的urls.py
"""emarket URL Configuration
The `urlpatterns` list routes URLs to views. For more information please see:
https://docs.djangoproject.com/en/3.2/topics/http/urls/
Examples:
Function views
1. Add an import: from my_app import views
2. Add a URL to urlpatterns: path('', views.home, name='home')
Class-based views
1. Add an import: from other_app.views import Home
2. Add a URL to urlpatterns: path('', Home.as_view(), name='home')
Including another URLconf
1. Import the include() function: from django.urls import include, path
2. Add a URL to urlpatterns: path('blog/', include('blog.urls'))
"""
from os import name
from django.contrib import admin
from django.urls import path
from myapp import views
from django.conf.urls.static import static
from django.conf import settings
urlpatterns = [
path('admin/', admin.site.urls),
path('',views.home,name='home'),
path('shop/',views.shop,name='shop'),
path('login/',views.create_user,name='login'),
path('logout/',views.user_logout,name='logout'),
path('cart/',views.productcart,name='cart'),
path('checkout/',views.checkout,name='checkout'),
path('product_detail/',views.product_detail,name='prodct-detail'),
path('find_us/',views.find_us,name='find'),
path('blog/',views.blog,name='blog'),
path('base/',views.base),
path('api/categories',views.all_categories,name="all_categories"),
path('api/brand',views.brand,name="brand"),
path('api/products',views.product_filter_api,name="product_filter_api"),
path('user_check/',views.check_user,name="check_user"),
path('filter_product/',views.filter_product,name="filter_product"),
path('add_to_favourite/',views.add_to_favourite,name="add_to_favourite"),
path('all_favourites/',views.all_favourites,name="all_favourites"),
path('forgotpass',views.forgotpass,name="forgotpass"),
path('resetpass',views.resetpass,name="resetpass"),
path('get_cart_data',views.get_cart_data,name="get_cart_data"),
path('change_quan',views.change_quan,name='change_quan'),
]+static(settings.MEDIA_URL,document_root=settings.MEDIA_ROOT)
我的models.py
class cart(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
product = models.ForeignKey(Product,on_delete=models.CASCADE)
image = models.ImageField(default=False)
total_price=models.FloatField(default=False)
quantity = models.IntegerField()
status = models.BooleanField(default=False)
added_on = models.DateTimeField(auto_now_add=True)
updated_on = models.DateTimeField(auto_now=True)
def __str__(self):
return self.user.username
我的html代码
{% extends 'base.html' %}
{% block head %}
<style>
.k{height: 1px;background-color: rgb(211, 207, 207);}
.s{color:rgb(240, 240, 240);
letter-spacing: 3px;
font-family:-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
font-weight: 400;}
.cncl_icn{
float: left;
margin: 15px;
padding-top: 10px;
}
.a:hover{
background-color:rgba(152, 209, 255, 0.705);color: rgb(255, 255, 255);box-shadow:0px 0px 7px 7px rgba(204, 201, 201, 0.5) ;
}
@media screen and (max-width:680px){
.b{opacity: 0;}
/* .v{position: absolute;top: 5px;} */
.s{font-size: 15px;}
}
@media screen and (min-width:1024px){
.s{font-size: 20px;}
}
</style>
{% endblock %}
{% block body %}
{% if user.is_superuser %}
<div class="container-fluid "></div>
<h1 class="jumbotron my-5" >you are not Allowed here</h1>
{% else %}
{% if status %}
<h1 class="jumbotron my-5">{{status}}</h1>
{% else %}
{% if msg %}
<div class="{{cls}}">{{msg}}</div>
{% endif %}
<div class="row v " style="margin-right: 0%;">
<div class="col-lg-7" >
<div class="row text-center p-3 b" style="background-color: rgba(2, 184, 184, 0.863); background-attachment: fixed;">
<div class="col-md-3 "> <h3 class="s">Product</h3></div>
<div class="col-md-3 "><h3 class="s">Price</h3></div>
<div class="col-md-3 "><h3 class="s">Qantity</h3></div>
<div class="col-md-3 "><h3 class="s">Total</h3></div>
</div>
{% for i in items %}
<div class="row a border-bottom" id="col{{i.product.id}}">
<div class="col-md-3 text-center " >
<i class="far fa-times-circle cncl_icn" id="cross{{i.product.id}}" style="font-size: 30px;"></i>
<img class="mt-4" src="/media/{{i.image}}" alt="check ur internet!" height="150px">
<a href="/product_detail/?id={{i.product.id}}" style="text-decoration: none;"><h4 class="ml-5" style="color: black;">{{i.product.name}}</h4></a>
<p class="ml-5">Size:{{i.product.size}} , color:{{i.product.color}}</p>
</div>
<div class="col-md-3 text-center mt-5">
{%if i.total_price < i.product.price%}
<del style="font-weight: bold; color: grey;" >${{i.product.price}}</del> $<p class="d-inline" style="font-weight: bold;" id="price{{i.product.id}}">{{i.total_price}}</p>
{% else %}
$<p class="d-inline" style="font-weight: bold;" id="price{{i.product.id}}">{{i.product.price}}</p>
{% endif %}
</div>
<div class="col-md-3 text-center">
<div class="form-group mt-4">
<div class="input-group">
<div class="input-group-btn ">
<button id="down" class="btn btn-default" onclick="change_quan('{{i.product.id}}','minus')" style="font-size: 25px;background: none;border: none;font-weight: bold;">-</button>
</div>
<input type="number" id="cart{{i.product.id}}" class="form-control text-center pt-3" value="{{i.quantity}}" style="width: 30px;border: none;font-weight: bold;background: none;">
<div class="input-group-btn">
<button id="up" class="btn btn-default" onclick="change_quan('{{i.product.id}}','plus')" style="font-size: 25px;background: none;border: none;font-weight: bold;">+</button>
</div>
</div>
</div>
</div>
<div class="col-md-3 mt-5 text-center">
{%if i.total_price < i.product.price %}
$<p class="d-inline" style="font-weight: bold;" id="total{{i.product.id}}">{{i.total_price}}</p>
{% else %}
$<p class="d-inline" style="font-weight: bold;" id="total{{i.product.id}}">{{i.product.price}}</p>
{% endif %}
</div>
</div>
<script>
$(function() {
$("#cross{{i.product.id}}").hover(function() {
$("#cross{{i.product.id}}").toggleClass("fas fa-times-circle").toggleClass("far fa-times-circle")
})
// to remove product from cart
$("#cross{{i.product.id}}").confirm({
title: 'Confirm',
content: 'Are you sure to remove this product from cart',
theme: 'modern',
buttons:{
confirm: function() {
$('#col{{i.product.id}}').remove()
},
cancel: function (){}
}
})
})
</script>
{% endfor %}
</div>
<script>
function grandTotal(){
$.ajax({
url:"{% url 'get_cart_data' %}",
type:'get',
success:function(data){
p = Math.round((data.offer/data.total)*100,2)
$('.item_total').html("$"+data.total)
$('#offer').html("$"+data.offer)
$('#per').html("("+p+"%)")
$('#quantity').html(data.quan)
c = (data.total)-(data.offer)
$('#grand_Total').html("$"+c)
}
})
}
grandTotal()
function change_quan(id,action){
let old = $("#cart"+id).val();
quan = 0
if(action=="plus"){
quan+=parseInt(old)+1
$('#total'+id).text( parseFloat($('#total'+id).text()) + parseFloat($('#price'+id).text()))
}
else{
quan+=parseInt(old)-1
$('#total'+id).text( parseFloat($('#total'+id).text()) - parseFloat($('#price'+id).text()))
}
$("#cart"+id).val(quan);
$.ajax({
url:"{% url 'change_quan' %}",
type:"get",
data:{cid:id,quantity:quan},
success:function(data){
alert(data)
}
});
}
</script>
<div class="col-md-5 text-center py-5" style="background-color: rgba(255, 176, 218, 0.397);">
<div id="cartt"></div>
<div class="row">
<img src="/static/Images/estore1.png" alt="" height="300px" style="margin: auto;">
</div>
<div class="pb-3 " style="font-size:30px;font-weight: bold;">--------------------</div>
<h4 class="pt-3" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">Total: <span style="font-size: 28px;" class="item_total"></span></h4>
<h4 class="pt-1" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">Quantity: <span style="font-size: 28px;" id="quantity"></span><span style="text-transform: none;"> Items</span></h4>
<h4 class="pt-1" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">You Saved: <span style="font-size: 28px;" id="offer"></span><span class='text-success'style="font-size: 20px;" id="per"></span></h4>
<h4 class="py-1" style="font-family: Arial, Helvetica, sans-serif;letter-spacing: 3px;text-transform: uppercase;">Grand Total: <del style="font-size: 25px; color:grey;" class="item_total"></del><span style="font-size: 28px;" id="grand_Total"></span></h4>
<h4 class="pt-3">Shipping charges will calculated at checkout</h4>
<form class="pt-3" action="" >
<!-- <input type="text" placeholder="Coupon code.." name="cod" class="mt-3 text-center" style="letter-spacing: 2px;font-size: 20px;border-radius: 25px;width: 250px;height: 47px;background-color: rgb(255, 255, 255);border:2px solid thistle;" >
<input type="submit" class="mt-3" value="Apply Code"name="acd" style="letter-spacing: 2px;font-size: 25px;border-radius: 25px;border: none;width: 250px;height: 45px;background-color: rgb(161, 158, 158);color: rgb(255, 255, 255);" > -->
<input type="submit" value="CHECKOUT" name="che" class="mt-5" style="letter-spacing: 2px;font-size: 25px;border-radius: 25px;border: none;width: 250px;height: 45px;background-color: black;color: rgb(255, 255, 255);" >
</form>
</div>
</div>
{% endif %}
</div>
{% endif %}
{% endblock %}
如果数据不存在'get_object_or_404' 将抛出 404 错误，根据您的要求您正在尝试使用主键 1 检索数据，但数据不可用 这就是您收到此错误的原因。所以请检查你 table 或尝试使用其他 pk 值
def change_quan(request):
qty = request.GET["quantity"]
cid = request.GET["cid"]
print(request.GET)
cart_obj = get_object_or_404(cart,id=cid) # please check this cid value
cart_obj.quantity = qty
cart_obj.save()
return HttpResponse(1)
get_object_or_404 在这里不是正确的选择。由于在数据库中找不到带有 id=cid 的对象，因此引发了 404 错误。这是 get_object_or_404.
您是否打算使用 get_or_create 对象以防找不到试图从数据库中获取的对象？