如何使用QuerySets和MySql“全文搜索”使Django在多个字段中进行搜索?

7
我是一名Django新手,正在尝试使用MySql和MyISAM引擎为我的项目创建一个“搜索”表单。到目前为止,我设法让表单工作,但是Django似乎无法以相同的方式搜索所有字段。结果是随机的。例如:在region中搜索不返回任何结果,而在description中搜索正常工作,而howtogetin似乎不适用。
以下是我的模型:
class Camp(models.Model):
    owner = models.OneToOneField(User)
    name = models.CharField(max_length=100)
    description = models.TextField()
    address1 = models.CharField(max_length=128)
    address2 = models.CharField(max_length=128)
    zipcode = models.CharField(max_length=128)
    region = models.CharField(max_length=128)
    country = models.CharField(max_length=128)
    phone = models.CharField(max_length=60)
    howtogetin = models.TextField()

    def __str__(self):
        return self.name

这是我的看法:
def campsearch(request):
if request.method == 'POST':
    form = CampSearchForm(request.POST)
    if form.is_valid():
        terms = form.cleaned_data['search']
        camps = Camp.objects.filter(
            Q(name__search=terms)|
            Q(description__search=terms)|
            Q(address1__search=terms)|
            Q(address2__search=terms)|
            Q(zipcode__search=terms)|
            Q(region__search=terms)|
            Q(country__search=terms)|
            Q(howtogetin__search=terms)
            )
        return render(request, 'campsearch.html', {'form':form, 'camps':camps})
else:
    form = CampSearchForm()
    return render(request, 'campsearch.html', {'form':form})

有线索吗?
2个回答

13
我建议您实现以下内容:
#views.py
def normalize_query(query_string,
    findterms=re.compile(r'"([^"]+)"|(\S+)').findall,
    normspace=re.compile(r'\s{2,}').sub):

    '''
    Splits the query string in invidual keywords, getting rid of unecessary spaces and grouping quoted words together.
    Example:
    >>> normalize_query('  some random  words "with   quotes  " and   spaces')
        ['some', 'random', 'words', 'with quotes', 'and', 'spaces']
    '''

    return [normspace(' ',(t[0] or t[1]).strip()) for t in findterms(query_string)]

def get_query(query_string, search_fields):

    '''
    Returns a query, that is a combination of Q objects. 
    That combination aims to search keywords within a model by testing the given search fields.
    '''

    query = None # Query to search for every search term
    terms = normalize_query(query_string)
    for term in terms:
        or_query = None # Query to search for a given term in each field
        for field_name in search_fields:
            q = Q(**{"%s__icontains" % field_name: term})
            if or_query is None:
                or_query = q
            else:
                or_query = or_query | q
        if query is None:
            query = or_query
        else:
            query = query & or_query
    return query

对于每个搜索

 #views.py
 def search_for_something(request):
    query_string = ''
    found_entries = None
    if ('q' in request.GET) and request.GET['q'].strip():
        query_string = request.GET['q']
        entry_query = get_query(query_string, ['field1', 'field2', 'field3'])
        found_entries = Model.objects.filter(entry_query).order_by('-something')

    return render_to_response('app/template-result.html',
            { 'query_string': query_string, 'found_entries': found_entries },
            context_instance=RequestContext(request)
        )

在模板中

#template.html
<form class="" method="get" action="{% url 'search_for_something' model.pk %}">
    <input name="q" id="id_q" type="text" class="form-control" placeholder="Search" />
    <button type="submit">Search</button>
</form>

#template-result.html
{% if found_entries %}
   {% for field in found_entries %}
        {{ model.field }}
   {% endfor %}
{% endif %}

并且这是网址

 #urls.py
 url(r'^results/$', 'app.views.search_for_something', name='search_for_something'),

1
我在互联网上看到过类似的东西,但我真的无法弄清它是如何工作的。你测试过吗?你能解释一下为什么它比Django默认的searchincontains实现更好吗? - adilbenseddik
1
嗨adilbenseddik,是的,我在我的项目中使用它,而且它运行得很好。这种方法是由Julien Phalip在http://julienphalip.com/post/2825034077/adding-search-to-a-django-site-in-a-snap提供的。 - Ronaldo Bahia
1
我会试一下。谢谢你的参考。但是,你有没有什么想法,关于我的代码哪里出了问题?根据Django的文档,它应该能够很容易地工作。 - adilbenseddik
2
嗨--@Ronaldo-Bahia,我对Julien Phalip的代码片段进行了一些更改/修正,现在我已经实现了搜索功能的单个视图。你应该检查我的最后一篇帖子这里;你可能会感兴趣。 - adilbenseddik
我已经更新了答案,以修复错误normalize_query(之前它返回的是“withquotes”而不是“with quotes”字符串(请参见docstring)。 - WTK
为了使规范化更加健壮,您可以在normalize_query函数中使用标准库shlex模块:[' '.join(q.split()) for q in shlex.split(query_string)] - Dustin Wyatt

1

我最终使用了Q(name__search=terms)|Q(name__icontains=terms)来扩展结果的范围,它起到了作用。但有些情况下结果是随机的。例如,如果数据库中有_foo_和_foo2_,则对'foo foo2'的搜索无法工作,而对'foo and random string'的搜索却可以正常工作。一些搜索术语似乎被忽略了,即使它们与一个存在的Q条件相匹配。有什么线索吗? - adilbenseddik

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