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python - Django - 查询集结果未显示在模板中

问题描述

我正在学习 Django 并为实验室构建一个库存应用程序。我的所有模型中都已经有了数据，现在我想根据一些条件搜索数据库并将结果显示在表格中。首先我要求用户输入搜索词（这部分有效），然后我查询数据库（这也有效），但是当显示结果时，我得到的只是一个空模板。没有错误信息。

这些是我的看法：

def choose_filter_primers(request):   # this works fine
    if request.method == "GET":
        radiobtn_form = PrimerRadiobtn(request.GET)
        
        if radiobtn_form.is_valid():
            # get value from user input and store it in request.session dict
            request.session['filter_by'] = radiobtn_form.cleaned_data['CHOOSE_FIELD']
            # go to the next step in the search form
            return render(request, 'lab_inventory/filter_primers.html')
    else:
        radiobtn_form = PrimerRadiobtn()
    
    return render(request, 'lab_inventory/choose_filter_primers.html', {'radiobtn_form': radiobtn_form})


def filter_primers(request):    # this works fine
    # get filter field from views.choose_filter_primers
    filter_by = request.session.get('filter_by')

    if request.method == "POST":
        form = FilterPrimerForm(request.POST)# or None)
        if form.is_valid():
            # get value from user input and store it in request.session dict
            request.session['contains'] = form.cleaned_data.get("contains")           
            # go to the next step in the search form
            return render(request, 'lab_inventory/search_results_primers.html')
        else:
            return render(request, 'lab_inventory/choose_filter_primers.html')
    else:
        form = FilterPrimerForm(request.POST)
        context = {'form': form}
        
    return render(request, 'lab_inventory/filter_primers.html', context)


def search_results_primers(request):   # MY PROBLEM IS HERE SOMEWHERE
    search_term = request.GET['contains'] # this variable refers to the value 'Ha'
    filter_by = request.session.get('filter_by') # this variable refers to the value 'primer_name'

    if filter_by == 'primer_name':
        query = Primer.objects.filter(primer_name__contains=search_term).values()
        result = {'query': query}
        
        return render(request, 'lab_inventory/search_results_primers.html', result)

中的查询search_results_primers返回这个（在 shell 中运行它）：

<QuerySet [{'id': 303, 'primer_name': 'Ha-9-F', 'primer_seq': '5-TAGCTAACTTGGCCTGAAGCCTC-3', 'purchase_order': 201, 'date_received': datetime.date(2001, 1, 16), 'date_opened': datetime.date(2001, 1, 30), 'date_discarded': datetime.date(2001, 2, 27), 'stored_freezer': '-20/3', 'stored_box': 'H / 2'},
 {'id': 304, 'primer_name': 'Ha-9-R', 'primer_seq': '5-TCTCCCTCCGAAGCAGGTTTCGCGG-3', 'purchase_order': 201, 'date_received': datetime.date(2001, 1, 16), 'date_opened': datetime.date(2001, 1, 30), 'date_discarded': datetime.date(2001, 2, 27), 'stored_freezer': '-20/3', 'stored_box': 'H / 3'},
 {'id': 311, 'primer_name': 'Ha-10-F', 'primer_seq': '5-GTCCTGAATCATGTTTCCCCTGCAC-3', 'purchase_order': 205, 'date_received': datetime.date(2003, 12, 19), 'date_opened': datetime.date(2004, 1, 2), 'date_discarded': datetime.date(2004, 1, 30), 'stored_freezer': '-20/1', 'stored_box': 'F / 7'},]  '...(remaining elements truncated)...']>

没错，这是我想要的搜索结果，到目前为止还不错。但是它只是返回一个空模板，它不显示任何数据。

这是我的模板：

    <table id="search-results-primers-table">
      <tr>
        <th>Primer Name</th>
        <th>Primer Sequence</th>
        <th>Purchase Order</th>
        <th>Date Received</th>
        <th>Date Opened</th>
        <th>Date Discarded</th>
        <th>Freezer / Shelf</th>
        <th>Box / Position</th>
      </tr>
      <tbody>
        {% for item in result %}
          <tr>
            <td>{{ item.primer_name }}</td>
            <td>{{ item.primer_seq }}</td>
            <td>{{ item.purchase_order }}</td>
            <td>{{ item.date_received }}</td>
            <td>{{ item.date_opened }}</td>
            <td>{{ item.date_discarded }}</td>
            <td>{{ item.stored_freezer }}</td>
            <td>{{ item.stored_box }}</td>
          </tr>      
        {% endfor %}
      </body>
    </table>

I have tried iterating as explained here, I have reorganized result using dictionary = {i: d for i, d in enumerate(queryset)}, and whatever else I could find but it just won't work, I know the problem has to be in the result that I am passing to render, or in {% for item in result %}, but I am so stuck with this, I have spent hours on this and still no results. I need a pair of fresh eyes to take a look and tell me what is it I'm doing wrong.

标签： pythondjangotemplatesviewdjango-queryset

解决方案

Since in the context, the queryset was passed in the keyword query, you need to use that same keyword in the template so:

{% for item in query %}
    ...

About this error:

didn't return an HttpResponse object. It returned None instead.

This can happen in search_results_primers if filter_by is not 'primer_name', causing your view to return nothing. To fix it, make sure your view returns a response when filter_by is not primer_name.

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