如何解决Django网站中Filter过滤器与Paginator分页器无法同时生效问题

问题根源 #

1. 分页器使用了未过滤的全量数据集，而非过滤后的查询结果，导致过滤和分页的数据源不统一
2. 分页跳转链接未携带过滤参数，切换页码时过滤条件丢失
3. filters.py中存在笔误，可能导致过滤规则不生效

修复步骤 #

1. 修改views.py中的分页逻辑 #

将分页器的数据源替换为过滤后的查询集：

def posts(request):
    cars = Userpost.objects.all()
    myFilter = UserpostFilter(request.GET, queryset=cars)
    # 拿到过滤后的结果集
    filtered_cars = myFilter.qs
    # 分页器使用过滤后的结果，而非全量数据
    p = Paginator(filtered_cars, 2)
    page = request.GET.get('page')
    cars_list = p.get_page(page)
    nums = "a" * cars_list.paginator.num_pages

    context = {"myFilter":myFilter, 'cars_list':cars_list, "nums":nums}
    return render(request, 'store/userposts.html', context)

2. 修复userposts.html模板 #

• 列表循环改为使用分页后的数据集cars_list
• 所有分页链接新增过滤参数携带逻辑，避免切换页码时过滤条件丢失

{% extends 'store/main.html' %}
{% load static %}

{% block content %}

<div class = 'row'>
  <div class = 'col'>
    <div class = 'card card-body'>
        <form method="get">
          {{myFilter.form}}
        <button class="btn btn-primary" type = "submit">Search</button>
        </form>
    </div>
  </div>
</div>

<div class="row">
    <!-- 循环改为分页后的过滤结果 -->
    {% for car in cars_list %}
    <div class="col-lg-4">
        <img class="thumbnail" src="{{car.imageURL|default:'/images/transparentLogo.png'}}">
        <div class="box-element product">
            <h6><strong>{{car.Year}} {{car.Make}} {{car.Model}}</strong></h6>
            <hr>
            <a class="btn btn-outline-success" href="{% url 'post_detail' car.pk %}">View</a>
            <h4 style="display: inline-block; float: right"><strong>${{car.Price|floatformat:2}}</strong></h4>

        </div>
    </div>
    {% endfor %}
</div>


<nav aria-label="Page navigation">   <ul class="pagination">
    {% if cars_list.has_previous %}
    <li class="page-item">
      <!-- 链接携带现有过滤参数 -->
      <a class="page-link" href="?{% for k,v in request.GET.items %}{% if k != 'page' %}{{k}}={{v}}&{% endif %}{% endfor %}page=1" aria-label="Previous">
        <span aria-hidden="true">&laquo;</span>
        <span class="sr-only">begin</span>
      </a>
    </li>   {% endif %}
    
    {% for n in cars_list.paginator.page_range %}
      {% if cars_list.number == n %}
        <li class="page-item active">
          <span class="page-link">{{ n }}<span class="sr-only">(current)</span></span>
        </li>
      {% elif n > cars_list.number|add:'-3' and n < cars_list.number|add:'3' %}
        <!-- 链接携带现有过滤参数 -->
        <li class="page-item"><a class="page-link" href="?{% for k,v in request.GET.items %}{% if k != 'page' %}{{k}}={{v}}&{% endif %}{% endfor %}page={{ n }}">{{ n }}</a></li>
      {% endif %}
    {% endfor %}
    
    {% if cars_list.has_next %}
      <li class="page-item">
        <!-- 链接携带现有过滤参数 -->
        <a class="page-link" href="?{% for k,v in request.GET.items %}{% if k != 'page' %}{{k}}={{v}}&{% endif %}{% endfor %}page={{ cars_list.paginator.num_pages }}" aria-label="Next">
          <span aria-hidden="true">&raquo;</span>
          <span class="sr-only">end</span>
        </a>
      </li>
      {% endif %}   </ul> </nav>

<br/>
    
{% endblock content %}

3. 修复filters.py的笔误 #

将field = '__all__'改为fields = '__all__'，避免过滤规则加载失败：

class UserpostFilter(django_filters.FilterSet):
    start_date = DateFilter(field_name = "date_published", lookup_expr = 'gte')
    end_date = DateFilter(field_name = "date_published", lookup_expr = 'lte')
    min_price = django_filters.NumberFilter(field_name="Price", lookup_expr='gte')
    max_price = django_filters.NumberFilter(field_name="Price", lookup_expr='lte')
    class Meta:
        model = Userpost
        # 修正为fields
        fields = '__all__'
        exclude = 'image', 'user', 'Price', 'Email', 'date_published'

4. 确认请求上下文配置 #

检查项目settings.py中TEMPLATES配置，确保已加入request上下文处理器，否则模板无法获取request对象携带的过滤参数：

TEMPLATES = [
    {
        # ... 其他配置
        'OPTIONS': {
            'context_processors': [
                # ... 其他处理器
                'django.template.context_processors.request', # 新增这行（如果不存在的话）
            ],
        },
    },
]

内容的提问来源于stack exchange，提问作者Gabriel Trezza