Django - 无法按外键first_name过滤

问：

所以目前我正在这样做，你可以通过一些过滤器来搜索正在参加偶数的用户first_name, last_name, username

当前错误

要解压缩的值太多（预期为 2）

视图中的误差线：

makefilter = "user__"+searchfilter+"__contains="+searchinput

usersearch = TeamMembership.objects.filter(makefilter)

如何通过过滤器成功搜索？

我 views.py：

def volunteer(request):
    ## init context
    context = {}
    ## Get filters if somes
    searchfilter = request.GET.get('filter', None)
    searchinput = request.GET.get('searchinput', None)
    ## Checks if filter is not none or null or empty
    if searchfilter != "" and searchfilter != None and searchinput != "" and searchinput != None:
        ## Great now check what filter is used
        ## Now strip the filters for whitespaces
        searchfilter.strip()
        searchinput.strip()
        ## This filter is for teams
        if searchfilter == "teamname":
            teamsearch = Team.objects.all().filter(name__contains=searchinput)
            context['teams'] = True
            context['search'] = teamsearch
        ## This filter is for users
        elif searchfilter == "first_name" or searchfilter == "last_name" or searchfilter == "username" or searchfilter == "phone":
            makefilter = "user__"+searchfilter+"__contains="+searchinput
            usersearch = TeamMembership.objects.filter(makefilter)
            context['users'] = True
            context['search'] = usersearch
    return render(request, 'volunteer/hqvolunteer.html', context)

我的模型我试图搜索用户模型是标准的 Django 身份验证：

class TeamMembership(models.Model):
    user = models.ForeignKey(User)
    team = models.ForeignKey(Team)
    ingroup = models.BooleanField(default=False)
    leader = models.BooleanField(default=False)
    groupleader = models.BooleanField(default=False)