加载没有搜索按钮的网址

Question

DJANGO/Python 我正在尝试加载http://127.0.0.1:8000/catalog/。如果用户在此页上的中输入数据，则表单将向数据库发送搜索查询。我的问题是http://127.0.0.1:8000/catalog/没有加载–它导致了一个异常值为“search\u query”的“MultiValueDictKeyError”异常类型。但是，当用户将数据提交到表单中时，（即http://127.0.0.1:8000/catalog/?search_query=biography+of），页面将被加载。我试图让http://127.0.0.1:8000/catalog/加载而用户不必提交搜索查询

以下是我的视图函数：

def index(request):
   . . .
     num_of_word = []
     bookInstance_titles = []
     bookInstance_ids = []
     num_of_word = BookInstance.objects.filter(status='a',      book__title__contains=request.GET['search_query']).count()
bookInstances = BookInstance.objects.filter(status='a', book__title__contains=request.GET['search_query'])
     for i in bookInstances:
        bookInstance_titles.append(str(i.book))
        bookInstance_ids.append(str(i.id))

    context = {
    . . .
    'num_of_word': num_of_word,
    'bookInstance_titles': bookInstance_titles,
    'bookInstance_ids': bookInstance_ids,
}

我认为问题在于变量（num\ of\ word和bookInstances）试图访问请求的搜索查询，而/catalog/request没有搜索查询。经过研究，我仍然不知道如何解决这个问题

谢谢你

Answer 1

希望能成功。根据您的代码使用下面的代码

    if request.method == 'GET' and 'q' in request.GET: #q is search Input field reference 
        num_of_word = []
        bookInstance_titles = []
        bookInstance_ids = []
        num_of_word = BookInstance.objects.filter(status='a', book__title__contains=request.GET.get('search_query', '').count()
        bookInstances = BookInstance.objects.filter(status='a', book__title__contains=request.GET.get('search_query', ''))
        for i in bookInstances:
            bookInstance_titles.append(str(i.book))
            bookInstance_ids.append(str(i.id))
        context = {
            . . .
            'num_of_word': num_of_word,
            'bookInstance_titles': bookInstance_titles,
            'bookInstance_ids': bookInstance_ids,
        }
    else{
        context = {
             . . .
             'num_of_word': "", #What you want to pass
             'bookInstance_titles': "", #What you want to pass
             'bookInstance_ids': "",  #What you want to pass
        }
    }

Answer 2

您尝试在GET查询不存在时访问它。您必须检查request.GET中是否存在search\u查询，或者只对其使用.GET函数。见下表：

def index(request):
     . . .
     num_of_word = []
     bookInstance_titles = []
     bookInstance_ids = []
     num_of_word = BookInstance.objects.filter(status='a', book__title__contains=request.GET.get('search_query', '').count()
     bookInstances = BookInstance.objects.filter(status='a', book__title__contains=request.GET.get('search_query', ''))
     for i in bookInstances:
         bookInstance_titles.append(str(i.book))
         bookInstance_ids.append(str(i.id))
    context = {
         . . .
         'num_of_word': num_of_word,
         'bookInstance_titles': bookInstance_titles,
         'bookInstance_ids': bookInstance_ids,
    }