Django模板创建create_eq跳转链接时出现NoReverseMatch错误求助

1. 直接报错原因：urls.py路由语法错误 #

你写的create_eq路由中，id参数缺少左尖括号，导致Django无法正确识别参数类型，匹配失败。
原错误代码：

path('create-eq/<slug:track_slug>/<slug:instrument_slug>/int:id>/', views.create_eq, name='create_eq'),

修正后：

path('create-eq/<slug:track_slug>/<slug:instrument_slug>/<int:id>/', views.create_eq, name='create_eq'),

2. 模板传参错误 #

你在循环遍历乐器列表时，用了全局的instrument.slug而不是当前循环项的slug，会导致所有链接传的都是同一个乐器的slug：
原错误代码：

<a href="{% url 'create_eq' track.slug instrument.slug track.id %}"><h5>{{ items.title }}</h5></a>

修正后：

<a href="{% url 'create_eq' track.slug items.slug track.id %}"><h5>{{ items.title }}</h5></a>

3. create_eq视图逻辑错误 #

你用同一个id参数同时查询Track和Instrument，这会导致当Track和Instrument的id不一致时直接404，另外保存EQ时没有关联对应的track和instrument外键：
原错误代码：

@login_required
def create_eq(request, track_slug, instrument_slug, id):
    user = request.user
    track = get_object_or_404(Track, id=id)
    instrument = get_object_or_404(Instrument, id=id)
    if request.method == "POST":
        form = EQCreateForm(request.POST)
        if form.is_valid():
            data = form.save(commit=False)
            data.user = user
            data.save()
            return redirect('profile', slug=track.slug, id=track.id)
    else:
        form = EQCreateForm()
    return render(request, 'feed/create_eq.html', {'form': form })

修正后：

@login_required
def create_eq(request, track_slug, instrument_slug, id):
    user = request.user
    track = get_object_or_404(Track, id=id)
    # 根据传入的slug查询乐器，而不是用track的id查
    instrument = get_object_or_404(Instrument, slug=instrument_slug)
    if request.method == "POST":
        form = EQCreateForm(request.POST)
        if form.is_valid():
            data = form.save(commit=False)
            data.user = user
            # 补充关联外键
            data.track = track
            data.instrument = instrument
            data.save()
            return redirect('profile', slug=track.slug, id=track.id)
    else:
        form = EQCreateForm()
    return render(request, 'feed/create_eq.html', {'form': form })

4. instrument_detail视图逻辑优化 #

你当前的路由中instrument-detail/<slug:track_slug>/<int:id>/里的id是Track的id，你用这个id去查询Instrument逻辑不合理，如果你这个页面是展示单个Track下的所有乐器，不需要单独查instrument_obj，可以删掉对应代码：
修正后参考：

@login_required
def instrument_detail(request, track_slug, id):
    user = request.user
    track = get_object_or_404(Track, id=id)
    instruments = Instrument.objects.filter(track_id=track.id)
    if instruments.exists():
        context = {
            'instruments': instruments,
            'track': track,
        }
        return render(request, 'feed/instrument_detail.html', context)
    else:
        print('There are no instruments set in your track')
        return redirect('create_instrument', track_slug=track.slug, id=track.id)

内容的提问来源于stack exchange，提问作者mac95782