There was a problem with the button not working - django

Question

I am a student who wants to be good at Django. The button does not work. If you press the button in detail.html, I want to save the product in DB as if I purchased it. My goal is to get the buyer, date, and product code as written on views.py. However, even if you press the button now, you can't save it in DB. What's the problem?
model.py
class Join(models.Model):
join_code = models.AutoField(primary_key=True)
username = models.ForeignKey(Member, on_delete=models.CASCADE, db_column='username')
product_code = models.ForeignKey(Product, on_delete=models.CASCADE, db_column='product_code')
part_date = models.DateTimeField(auto_now_add=True)
def __str__(self):
return str(self.join_code)
class Meta:
ordering = ['join_code']
Join/views
from datetime import timezone
from django.shortcuts import render
from zeronine.models import *
def join_detail(request):
product = Product.objects.all()
if request.method == "POST":
join = Join()
join.product_code = product
join.username = request.user
join.part_date = timezone.now()
join.save()
return render(request, 'zeronine/detail.html', {'product': product})
detail.html
{% extends 'base.html' %}
{% block title %} 상품 상세보기 {% endblock %}
{% block content %}
<div class="container">
<div class="row">
<div class="col-4">
<img src="{{product.image.url}}" width="190%" style="margin-top: 35px;">
</div>
<div class="text-center col" style="margin-top:150px; margin-left:200px;">
<b><h4 class="content" style="margin-bottom: -5px;"><b>{{product.name}}</b></h4></b>
<br>
<div>
<!-- <span>주최자 : <b>{{ product.username }}</b></span><br>-->
<span style="color: #111111">모집기간 : <b>{{ product.start_date }} ~ {{ product.due_date }}</b></span>
</div>
<hr style="margin-top: 30px; margin-bottom: 30px;">
<p><span class="badge badge-dark">가격</span>
{% load humanize %}
{% for designated in designated_object %}
{% if designated.product_code.product_code == product.product_code %}
{{designated.price | floatformat:'0' | intcomma }}원
{% endif %}
{% endfor %}</p>
<span class="badge badge-dark">목표금액</span> {{ product.target_price | floatformat:'0' | intcomma }}원 <br><br>
<p class="badge badge-dark">공동구매 취지
{{product.benefit|linebreaks}}</p>
<p class="badge badge-dark">상세설명
{{product.detail|linebreaks}}</p>
<br>
<form action="" method="post">
{% csrf_token %}
<a onclick="alert('{{ product.name }} 공동구매 참여가 완료되었습니다.');" style="cursor:pointer;">
<form method="POST" action ="{% url 'zeronine:join_detail' %}">
{% csrf_token %}
<div class="form-group">
<button type="submit" action="{% url 'zeronine:join_detail' %}" class="btn btn-primary" style="float: right; background: #637B46; border: white">업로드</button>
</div>
</form>
</a>
</form>
</div>
</div>
</div>
{% endblock %}

Answer 1

I am not sure but you have a form inside a form in your template. maybe that is causing the problem.
also
in the POST section. it is best practice to use
join = Join.objects.create(product_code=product, ....)```