搜索多个单词elasticsearch haystack

Question

我曾经使用过django，haystack和elasticsearch。

我的search_index.py：

from haystack import indexes
from models import Advertisement



class AdvertisementIndex(indexes.SearchIndex, indexes.Indexable):
    text = indexes.CharField(document=True, use_template=True)
    make = indexes.CharField()
    section = indexes.CharField()
    subcategory = indexes.CharField()
    content = indexes.CharField(model_attr='content')
    images = indexes.CharField(model_attr='images')

    def get_model(self):
        return Advertisement

    def index_queryset(self, using=None):
        return self.get_model().objects.filter(is_published=True).select_related('make').select_related('section').select_related('subcategory')

搜索表格：

    <form action="/search" method="get">
        <input type="text-search" name="q">
        <input type="submit" value="">
    </form>

模板：

{% block content %}

{% for result in page.object_list %}
   <p>{{ result.object.title }}</p>
   <p>{{ result.object.content }}</p>
   <p>{{ result.object.images }}</p>
   <p>{{ result.object.make }}</p>
   <p>{{ result.object.section }}</p>
   <p>{{ result.object.subcategory }}</p>
{% empty %}
   <p>No result.</p>
{% endfor %}

{% endblock %}

看`curl -XGET "http://localhost:9200/_search?q=fender+boss" `
我得到所有的价值，那里有“老板”和“挡泥板”

当您在搜索框中输入“ boss fender”时，我没有结果。从搜索表单中，我只能得到一个单词的结果，例如“老板”。如何使搜索多个单词的能力？

Answer 1

这个月我陷入了这个问题。

为了执行正确的查询，您将需要覆盖一些干草堆对象。我发现这篇文章对扩展Haystack的Elasticsearch后端很有帮助。刚开始时非常复杂，但是一旦了解了它的工作原理… :-)

博客文章介绍了如何实现elasticsearch的嵌套查询…好吧…我已经实现了基本的multi_match查询。

# -*- coding: utf-8 -*-
from __future__ import absolute_import

from django.conf import settings

from haystack.backends.elasticsearch_backend import (
    ElasticsearchSearchBackend, ElasticsearchSearchEngine, ElasticsearchSearchQuery)
from haystack.query import SearchQuerySet


class ElasticsearchEngineBackendCustom(ElasticsearchSearchBackend):
    DEFAULT_ANALYZER = "snowball"

    def __init__(self, connection_alias, **connection_options):
        super(ElasticsearchEngineBackendCustom, self).__init__(connection_alias, **connection_options)

        user_settings = getattr(settings, 'ELASTICSEARCH_INDEX_SETTINGS', {})
        if user_settings:
            setattr(self, 'DEFAULT_SETTINGS', user_settings)

        user_analyzer = getattr(settings, 'ELASTICSEARCH_DEFAULT_ANALYZER', '')
        if user_analyzer:
            setattr(self, 'DEFAULT_ANALYZER', user_analyzer)

    def build_search_kwargs(self, query_string, sort_by=None, start_offset=0, end_offset=None,
                            fields='', highlight=False, facets=None,
                            date_facets=None, query_facets=None,
                            narrow_queries=None, spelling_query=None,
                            within=None, dwithin=None, distance_point=None,
                            models=None, limit_to_registered_models=None,
                            result_class=None, multi_match=None):

        out = super(ElasticsearchEngineBackendCustom, self).build_search_kwargs(query_string, sort_by, start_offset,
                                                                                end_offset,
                                                                                fields, highlight, facets,
                                                                                date_facets, query_facets,
                                                                                narrow_queries, spelling_query,
                                                                                within, dwithin, distance_point,
                                                                                models, limit_to_registered_models,
                                                                                result_class)

        if multi_match:
             out['query'] = {
                'multi_match': {
                    'query': multi_match['query'],
                    'fields': multi_match['fields'],
                    'tie_breaker': multi_match['tie_breaker'],
                    'minimum_should_match': multi_match['minimum_should_match'],
                }
            }

        return out

    def build_schema(self, fields):
        content_field_name, mapping = super(ElasticsearchEngineBackendCustom, self).build_schema(fields)

        for field_name, field_class in fields.items():
            field_mapping = mapping[field_class.index_fieldname]

            if field_mapping['type'] == 'string' and field_class.indexed:
                if not hasattr(field_class, 'facet_for') or field_class.field_type in ('ngram', 'edge_ngram'):
                    field_mapping['analyzer'] = getattr(field_class, 'analyzer', self.DEFAULT_ANALYZER)
            mapping.update({field_class.index_fieldname: field_mapping})

        return content_field_name, mapping

    def multi_match_run(self, query, fields, minimum_should_match, tie_breaker):
        from elasticsearch_dsl import Search
        from elasticsearch_dsl.query import MultiMatch

        raw = Search().using(self.conn).query(
            MultiMatch(query=u'{}'.format(query), fields=fields, minimum_should_match=minimum_should_match, tie_breaker=tie_breaker)
        ).execute()

        return self._process_results(raw)


class ElasticsearchSearchQueryCustom(ElasticsearchSearchQuery):
    def multi_match(self, query, fields, minimum_should_match, tie_breaker):
        results = self.backend.multi_match_run(query, fields, minimum_should_match, tie_breaker)
        self._results = results.get('results', [])
        self._hit_count = results.get('hits', 0)

    def add_multi_match_query(self, query, fields, minimum_should_match, tie_breaker):
        self.multi_match_query = {
            'query': query,
            'fields': fields,
            'minimum_should_match': minimum_should_match,
            'tie_breaker': tie_breaker
        }

    def build_params(self, spelling_query=None, **kwargs):
        search_kwargs = super(ElasticsearchSearchQueryCustom, self).build_params(spelling_query, **kwargs)
        if self.multi_match_query:
            search_kwargs['multi_match'] = self.multi_match_query

        return search_kwargs


class ElasticsearchSearchQuerySetCustom(SearchQuerySet):
    def multi_match(self, query, fields, minimum_should_match="35%", tie_breaker=0.3):
        clone = self._clone()
        clone.query.add_multi_match_query(query, fields, minimum_should_match, tie_breaker)
        clone.query.multi_match(query, fields, minimum_should_match, tie_breaker)
        return clone


class ElasticsearchEngineCustom(ElasticsearchSearchEngine):
    backend = ElasticsearchEngineBackendCustom
    query = ElasticsearchSearchQueryCustom

如您所见，我曾经elasticsearc- dsl执行查询（MultiMatch），这句话概括了博客文章：ElasticsearchSearchQuerySetCustom().multi_match(...)调用取决于ElasticsearchSearchQueryCustom，取决于ElasticsearchEngineBackendCustom。

然后在您的设置中放入elasticsearch配置，例如：

ELASTICSEARCH_DEFAULT_ANALYZER = 'italian'
ELASTICSEARCH_INDEX_SETTINGS = {
    "settings": {[...]}
}

您可以ELASTICSEARCH_INDEX_SETTINGS从语言分析器中获取您的语言

您还需要覆盖SearchForm：

# -*- coding: utf-8 -*-
from __future__ import absolute_import

from haystack.forms import SearchForm

from .backend import ElasticsearchSearchQuerySetCustom


class SearchFormCustom(SearchForm):
    def search(self):
        query = self.searchqueryset.query.clean(self.cleaned_data.get('q'))
        if not self.is_valid() or not query:
            return self.no_query_found()

        sqs = ElasticsearchSearchQuerySetCustom().multi_match(query, ['title^8', 'text^0.5'])

        return sqs

字段title和text必须在索引中，并且脱字符号用于对字段进行增强。

您需要覆盖haystack url模式才能使用自定义格式：

urlpatterns = patterns(
    'search.views',
    url('^$', search_view_factory(form_class=SearchFormCustom), name='haystack-search'),
)

就是这样，HTH :-)

注意
不要使用，result.object.something而是使用索引上的字段，例如result.tilte，因为result.object.tilte打数据库！参见干草堆最佳实践