Django之组合查询

一 .Django组合查询

很多电商网站中有组合搜索的功能,所谓组合搜索就是网页中组合多个条件,对数据库中进行查询,并且将结果显示在页面中,下面是所做组合查询效果图：

实现代码如下:

<1>设计数据库

from django.db import models

class Direction(models.Model):
    """
    方向：大数据，人工智能，web开发，系统运维，移动开发
    """
    name = models.CharField(verbose_name='名称', max_length=32)

    classification = models.ManyToManyField('Classification')

    class Meta:
        db_table = 'Direction'
        verbose_name_plural = '方向（视频方向）'

    def __str__(self):
        return self.name

class Classification(models.Model):
    """
    分类：Python PHP.......
    """
    name = models.CharField(verbose_name='名称', max_length=32)

    class Meta:
        db_table = 'Classification'
        verbose_name_plural = '分类（视频分类）'

    def __str__(self):
        return self.name

class Level(models.Model):
    title = models.CharField(max_length=32)

    class Meta:
        verbose_name_plural = '难度级别'

    def __str__(self):
        return self.title

class Video(models.Model):
    status_choice = (
        (1, '下线'),
        (2, '上线'),
    )

    status = models.IntegerField(verbose_name='状态', choices=status_choice, default=1)
    level = models.ForeignKey(Level,on_delete=models.CASCADE)
    classification = models.ForeignKey('Classification', null=True, blank=True,on_delete=models.CASCADE)

    weight = models.IntegerField(verbose_name='权重（按从大到小排列）', default=0)

    title = models.CharField(verbose_name='标题', max_length=32)
    summary = models.CharField(verbose_name='简介', max_length=32)
    # img = models.ImageField(verbose_name='图片', upload_to='./static/images/Video/')
    img = models.CharField(verbose_name='图片',max_length=32)
    href = models.CharField(verbose_name='视频地址', max_length=256)

    create_date = models.DateTimeField(auto_now_add=True)

    class Meta:
        db_table = 'Video'
        verbose_name_plural = '视频'

    def __str__(self):
        return self.title

modes.py

<2>配置url

from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
    url(r'^admin/', admin.site.urls),

    url(r'^video2-(?P<direction_id>(\d+))-(?P<classification_id>(\d+))-(?P<level_id>(\d+)).html$', views.video2),
]

<3>视图处理部分view.py

from django.shortcuts import render
from app01 import models

def video2(request,*args,**kwargs):
    condition = {}#video查询字典

    for k, v in kwargs.items():
        temp = int(v)
        kwargs[k] = temp
    print('kwargs:',kwargs) #　(?P<direction_id>(\d+))-(?P<classification_id>(\d+))-(?P<level_id>(\d+))
    # 构造查询字典
    direction_id = kwargs.get('direction_id')
    classification_id = kwargs.get('classification_id')
    level_id = kwargs.get('level_id')

    direction_list = models.Direction.objects.all()

    if direction_id == 0:#代表全部方向
        class_list = models.Classification.objects.all()
        if classification_id == 0:#代表全部课程分类
            pass
        else:
            condition['classification_id'] = classification_id
    else:
        direction_obj = models.Direction.objects.filter(id=direction_id).first()
        class_list = direction_obj.classification.all()#跨表查询所选方向下的所有课程分类
        print('class_list:',class_list)

        class_list_id = direction_obj.classification.all().values_list('id')
        if not class_list_id:
            classification_id_list = []
        else:
            classification_id_list = list(zip(*class_list_id))[0]

        if classification_id == 0:
            condition['classification_id__in'] = classification_id_list
        else:
            if classification_id in classification_id_list:#某课程分类在指定方向课程分类列表中
                condition['classification_id'] = classification_id
            else:
                # 某课程分类不在指定方向课程分类列表中
                kwargs['classification_id'] = 0
                condition['classification_id__in'] = classification_id_list

    if level_id == 0:
        pass
    else:
        condition['level_id'] = level_id
    print('condition:',condition)

    level_list = models.Level.objects.all()

    video_list = models.Video.objects.filter(**condition)

    return render(
        request,
        'video2.html',
        {
            'kwargs':kwargs,
            'direction_list':direction_list,
            'class_list':class_list,
            'level_list':level_list,
            'video_list':video_list

        }
    )

View.py

<4>页面显示部分

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .condition a{
            display: inline-block;
            padding: 5px 8px;
            border: 1px solid #dddddd;
            text-decoration: none;
        }
        .condition a.active{
            background-color: coral;
            color: white;
            text-decoration: none;
        }
    </style>
</head>
<body>
    <div class="condition">
        <h1>筛选</h1>
        <div>
            {% if kwargs.direction_id == 0 %}
                <a class="active" href="/video2-0-{{ kwargs.classification_id }}-{{kwargs.level_id}}.html">全部</a>
            {% else %}
                <a href="/video2-0-{{ kwargs.classification_id }}-{{kwargs.level_id}}.html">全部</a>
            {% endif %}
            {% for item in direction_list %}
                {% if item.id == kwargs.direction_id %}
                    <a class="active" href="/video2-{{ item.id }}-{{ kwargs.classification_id }}-{{kwargs.level_id}}.html">{{ item.name }}</a>
                {% else %}
                    <a href="/video2-{{ item.id }}-{{ kwargs.classification_id }}-{{kwargs.level_id}}.html">{{ item.name }}</a>
                {% endif %}
            {% endfor %}
        </div>
        <div>
            {% if kwargs.classification_id == 0 %}
                <a class="active" href="/video2-{{ kwargs.direction_id}}-0-{{kwargs.level_id}}.html">全部</a>
            {% else %}
                <a  href="/video2-{{ kwargs.direction_id}}-0-{{kwargs.level_id}}.html">全部</a>
            {% endif %}
            {% for item in class_list %}
                {% if item.id == kwargs.classification_id %}
                   <a class="active" href="/video2-{{ kwargs.direction_id }}-{{ item.id }}-{{kwargs.level_id }}.html">{{ item.name }}</a>
                {% else %}
                   <a  href="/video2-{{ kwargs.direction_id }}-{{ item.id }}-{{kwargs.level_id }}.html">{{ item.name }}</a>
                {% endif %}
            {% endfor %}
        </div>
        <div>
            {% if kwargs.level_id == 0 %}
                <a class="active" href="/video2-{{ kwargs.direction_id}}-{{ kwargs.classification_id }}-0.html">全部</a>
            {% else %}
                 <a  href="/video2-{{ kwargs.direction_id}}-{{ kwargs.classification_id }}-0.html">全部</a>
            {% endif %}
            {% for item in level_list %}
                {% if item.id == kwargs.level_id %}
                    <a class="active" href="/video2-{{ kwargs.direction_id }}-{{ kwargs.classification_id }}-{{ item.id }}.html">{{ item.title }}</a>
                {% else %}
                    <a href="/video2-{{ kwargs.direction_id }}-{{ kwargs.classification_id }}-{{ item.id }}.html">{{ item.title }}</a>
                {% endif %}
            {% endfor %}
        </div>

    </div>
    <div>
        <h1>结果</h1>
        {% for row in video_list %}
            <div>{{ row.title }}</div>
            <img src="{{ row.img }}">
        {% endfor %}
    </div>
</body>
</html>

HTML

>>>>>>>待续