我试图使用bulk_create，这样我就可以保存到数据库，但我写的代码只能保存一个数据，但当我想保存多个数据时，它给了我这个错误“NoneType对象没有属性'pk'”
我试过这个，我的期望是保存所有的股份一次根据成员的人数

def new_share(request):
    success_count = 0
    group = GroupMember.objects.filter(user=request.user).first()
    attendance = Attendance.objects.filter(group=group,meeting__date=date.today())
    config = ConfigurationData.objects.filter(group=group).first()
    members = Member.objects.filter(group=group, is_active=True)

    for member in members:
        member.created_at = member.created_at.strftime('%Y-%m-%d') 
    members_json = json.dumps(list(members.values()),default=str) 
    attendance_data = [
                    {'member_id': data.member.id, 'attended': data.attended}
                    for data in attendance
                ]
    if not attendance:
        messages.warning(request,f'Please make sure you have take an attendance for this meeting before you buy a share.')

    if request.method == 'POST':
        member_ids = [key.split('_')[-1] for key in request.POST.keys() if key.startswith('amount_of_share_')]
        print(member_ids)
        instances = []
        for member_id in member_ids:
            member = get_object_or_404(Member,group=group,id=int(member_id))
            amount_key = 'amount_of_share_'+ member_id
            amount = int(request.POST.get(amount_key,0))
            print(f'amount is {amount} and for member {member}')
            if amount > 0:
                try:
                    instances.append(ShareManagement.buyshare(request,value=amount,member=member.id))
                    success_count +=1
                except Exception as e:
                    messages.error(request,f"Error processing data for {member.memberID}: {str(e)}") 
                    print(f'Error processing data for {member.memberID}: {str(e)}')
            else:
                print(f'Process the fine for not buying a share for member {member.memberID}') 
        print(instances)        
        Share.objects.bulk_create(instances)  
        if success_count > 0:
            messages.success(request,f'{success_count} shares have been successfully saved.')  
            return redirect('app:share')       
                
    context = {
        
        'attendance':json.dumps(attendance_data),
        'config':config,
        'members_json':members_json,
        'members':members
    }
    return render(request,'shares/add_share.html',context)

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