How can i get data from multiple table in django - django

Question

how can i get data from this below django html template
<form action="{% url 'purchase_order_item' p_order.id %}" method="post" enctype="multipart/form-data" class="form-group">
{% csrf_token %}
<table id="example-datatable" class="table table-vcenter table-condensed table-bordered">
<thead>
<tr>
<th>#</th>
<th>Name</th>
<th>Brand Name</th>
<th>Product Type</th>
<th>Category</th>
<th>SubCategory</th>
<th>Quantity</th>
<th>Unit Price</th>
<th>Action</th>
</tr>
</thead>
<tbody>
{% for p in product %}
<tr>
<td>{{p.id}}</td>
<td>
{{p.name}}
</td>
<td>{{p.brand}}</td>
<td>{{p.ptype}}</td>
<td>{{p.catname}}</td>
<td>{{p.supplier}}</td>
<td>
<input type="text" id="quantity" name="quantity" value="1" class="form-control">
</td>
<td>
<input type="text" id="unitprice" name="unitprice" value="1" class="form-control">
</td>
<td>
<button type="submit" class="btn btn-primary btn-xs">Add</button>
</td>
</tr>
{% endfor %}
</tbody>
</table>
</form>
views.py
def purchase_order_item(request,id):
now = datetime.datetime.now()
year = now.year
month = now.month
day = now.day
if (len(str(day))) == 1:
day = '0' + str(day)
if (len(str(month))) == 1:
month = '0' + str(month)
date = str(year) + '-' + str(month) + '-' + str(day)
randstrn = ""
for i in range(5):
randstrn = randstrn + random.choice(string.digits)
# catid = Cat.objects.get(name=name).pk
# news = News.objects.filter(ocatid=catid) # showing post based on master category
supplier = Supplier.objects.all()
p_order = Purchase_order.objects.get(pk=id)
product = Parts.objects.all()
# this is the form for getting data from html
if request.method == 'POST':
quantity = request.POST.get('quantity')
unit_price = request.POST.get('unitprice') # itemid = pk type
nameid = request.POST.get('quantity')
ref_num = Purchase_order.objects.get(pk=id).order_id
order_id = Purchase_order.objects.get(pk=id).order_id # get Purchase Order Id for Relational Referance
sv = Purchase_order_item(
ref_number=ref_num,
product_name='sample_name',
# product_brand='product_brand',
# product_type = 'product_type',
# product_cat = 'product_cat',
# product_sub_cat = 'k',
quantity=quantity,
unit_price = unit_price,
total_price = '12',
order_id=order_id
)
sv.save()
# return redirect('purchase_order_item_list')
return render(request,'back/purchase/assign_purchas_item.html',
{'p_order':p_order,'supplier':supplier,
'product':product}
)
This is my Models.py
class Purchase_order_item(models.Model):
# order_id = models.IntegerField(default=0) # this is a purchase order id for referance purpose and relation both
ref_number = models.IntegerField(default=0)
product_name = models.CharField(max_length=50) # generate an unique Rendome number for farther relation for invoice item
product_brand = models.CharField(max_length=50)
product_type = models.CharField(max_length=50) # genuine or after market
product_cat = models.CharField(max_length=50) # product name
product_sub_cat = models.CharField(max_length=50) # product name
quantity = models.IntegerField(default=0)
unit_price = models.FloatField(default=250)
total_price = models.FloatField()
order_id = models.IntegerField(default=0)
This is my Html screenshot
Now my question is that ..
how can i get all the listed data after click add button as like Name , brand name , product type , category , subcat , quantity , unit price , etc save to purchase_order_item table .
thanks in advance