django+django-haystack+Whoosh(后期切换引擎为Elasticsearch+ik)+Jieba+mysql

1.前提准备

环境介绍

  • haystack是django的开源搜索框架,该框架支持Solr, Elasticsearch, Whoosh, *Xapian*搜索引擎,不用更改代码,直接切换引擎,减少代码量。

  • 搜索引擎使用Whoosh,这是一个由纯Python实现的全文搜索引擎,没有二进制文件等,比较小巧,配置比较简单,当然性能自然略低。whoosh和xapian的性能差距还是比较明显。索引和搜索的速度有近4倍的差距,在full cache情况下的性能差距更是达到了60倍。

  • 中文分词+,由于Whoosh自带的是英文分词,对中文的分词支持不是太好,故用jieba替换whoosh的分词组件。

  • Elasticsearch:开源的搜索引擎,本文版本为7.6.0

  • 其他:Python3.6.5, Django2.2 

  • 安装环境

    pip3 install django==2.2 -i https://pypi.douban.com/simple
    pip3 install whoosh  -i https://pypi.douban.com/simple
    pip3 install django-haystack -i https://pypi.douban.com/simple
    pip3 install jieba -i https://pypi.douban.com/simple
    pip3 install pymysql -i https://pypi.douban.com/simple
    pip3 install elasticsearch==7.6.0 -i https://pypi.douban.com/simple/

    项目结构

     - Project
       - Project
         - settings.py
       - blog
         - models.py

    表结构

    models.py

    from django.db import models
    
    
    class UserInfo(models.Model):
        username = models.CharField(verbose_name='用户名', max_length=225)
    
        def __str__(self):
            return self.username
    
    
    class Tag(models.Model):
        name = models.CharField(verbose_name='标签名称', max_length=225)
    
        def __str__(self):
            return self.name
    
    
    class Article(models.Model):
        title = models.CharField(verbose_name='标题', max_length=225)
        content = models.CharField(verbose_name='内容', max_length=225)
        # 外键
        username = models.ForeignKey(verbose_name='用户', to='UserInfo', on_delete=models.DO_NOTHING)
        tag = models.ForeignKey(verbose_name='标签', to='Tag', on_delete=models.DO_NOTHING)
    
        def __str__(self):
            return self.title
    

    图解

    本文优势

    集全网的django+django-haystack+Whoosh的总结,取其精华,去其糟粕,加入了新的注解。

    如果你想你的es或者Whoosh集成到django上,那你来对地方了

    django+django-haystack+Whoosh+Jieba+mysql

    1. setting.py配置

    # 数据库配置
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.mysql',
            'NAME': 'dj_ha',
            'USER': 'root',
            'PASSWORD': 'foobared',
            'HOST': '106.14.42.253',
            'PORT': '11111',
        }
    }
    # app
    INSTALLED_APPS = [ 
              'haystack', 
    ]
    # 本教程使用的是Whoosh,故配置如下
    HAYSTACK_CONNECTIONS = {
        'default': {
            'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine',
            'PATH': os.path.join(os.path.dirname(__file__), 'whoosh_index'),
        },
    }
    # 自动更新索引
    HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'
    # 设置每页显示的数目,默认为20,可以自己修改
    HAYSTACK_SEARCH_RESULTS_PER_PAGE = 8
    

    2. 为表模型创建索引,search_indexes.py

    1. 如果你想针对某个app,例如blog做全文检索,则必须在blog的目录下面,建立search_indexes.py文件,文件名不能修改,必须叫search_indexes.py

    from haystack import indexes
    from .models import Article
    
    
    # ArticleIndex:固定写法 表名Index
    class ArticleIndex(indexes.SearchIndex, indexes.Indexable):
        # 固定写法  document=True:haystack和搜索引擎,将给text字段分词,建立索引,使用此字段的内容作为索引进行检索
        # use_template=True,使用自己的模板,与document=True进行搭配,自定义检索字段模板(允许谁可以被全文检索,就是谁被建立索引)
        text = indexes.CharField(document=True, use_template=True)
        # 以下字段作为辅助数据,便于调用,最后也不知道怎么辅助,我注释了,也不影响搜索
        # title:写入引擎的字段名,model_attr='title':相对应的表模型字段名,
        title = indexes.CharField(model_attr='title')
        content = indexes.CharField(model_attr='content')
        username = indexes.CharField(model_attr='username')
        tag = indexes.CharField(model_attr='tag')
    
        def get_model(self):
            # 需要建立索引的模型
            return Article
    
        def index_queryset(self, using=None):
            """Used when the entire index for model is updated."""
            # 写入引擎的数据,必须返回queryset类型
            return self.get_model().objects.all()
    

    3. 创建被检索的模板(允许谁可以全文检索)

    这个数据模板的作用是对Article.title, Article.content,Article.username.username

    这三个字段建立索引,当检索的时候会对这三个字段的内容,做全文检索匹配。

    数据模板的路径为yourapp/templates/search/indexes/yourapp/note_text.txt,

    例如本例子为blog/templates/search/indexes/blog/article_text.txt  文件名必须为要索引的小写模型类名_text.txt

    {{ object.title }}
    {{ object.content }}
    {{ object.username.username }}

    4. 路由

    urls.py配置(用内置的视图,后期可以自定义,本文也有介绍)

    # urls.py
    from django.contrib import admin
    from django.urls import path, include, re_path
    
    urlpatterns = [
        path('admin/', admin.site.urls),
        # 配置的搜索路由,路由可以自定义,include('haystack.urls')固定
        re_path(r'^search/', include('haystack.urls')),
    ]

     haystack.urls的内容(内置的,只是我拉出来,让你看一下,不需要进行修改)

    from django.urls import path
    
    from haystack.views import SearchView
    
    urlpatterns = [path("", SearchView(), name="haystack_search")]

    5. search.html

    SearchView()视图函数默认使用的html模板为当前app目录下,

    路径为app名称,/templates/search/search.html

    所以需要在blog/templates/search/下添加search.html文件,内容为

     search.html(原生)

    <h2>Search</h2>
    <style>
        span.highlighted {
            color: red;
        }
    </style>
    <!--高亮加载-->
    {% load highlight %}
    
    <form method="get" action=".">
        <table>
            <!-- 对象.as_table 生成表格,里边会自动成成input标签 -->
            {{ form.as_table }}
    
            {#        {{ form.title.label }}#}
            <tr>
                <td></td>
                <td>
                    <input type="submit" value="Search">
                </td>
            </tr>
        </table>
    
        {% if query %}
            <h3>返回结果</h3>
    
            {% for result in page.object_list %}
                <!-- page.object_list:返回查询的一页数据 -->
                <!-- result:数据对象 -->
                <p>
                    {#                <a href="{{ result.object.get_absolute_url }}">{{ result.object.title }}</a>#}
                    <a href="{{ result.object.get_absolute_url }}">{% highlight result.object.title with query %}</a>
                </p>
                <span>
                    {% highlight result.object.content with query %}
                    {#                {{ result.object.content }}#}
                </span>
    
            {% empty %}
                <p>没有查询到结果!!!</p>
            {% endfor %}
    
    
            <!-- 分页 -->
            {% if page.has_previous or page.has_next %}
                <div>
                    {% if page.has_previous %}<a href="?q={{ query }}&page={{ page.previous_page_number }}">{% endif %}«
                    Previous{% if page.has_previous %}</a>{% endif %}
                    |
                    {% if page.has_next %}<a href="?q={{ query }}&page={{ page.next_page_number }}">{% endif %}Next »
                    {% if page.has_next %}</a>{% endif %}
                </div>
            {% endif %}
        {% else %}
            {# Show some example queries to run, maybe query syntax, something else? #}
        {% endif %}
    </form>

     后端返回数据介绍

    # print(context)
            """
            {
            'query': '刘',
            'form': <ModelSearchForm bound=True, valid=True, fields=(q;models)>,
            'page': <Page 1 of 1>,
            'paginator': <django.core.paginator.Paginator object at 0x0000017D7E0F3470>,
            'suggestion': None}
            """
    # print(context.get('page').__dict__)
            """
            {
            'object_list': 
                [
                <SearchResult: blog.article (pk=6)>, 
                <SearchResult: blog.article (pk=8)>, 
                <SearchResult: blog.article (pk=1)>
            ], 
            'number': 1, 
            'paginator': <django.core.paginator.Paginator object at 0x00000257C11A65C0>
            }
            """

    前端返回数据介绍

    {% load highlight %}:高亮加载 内置的会省略搜到的内容,之前的内容
    {% load my_filters_and_tags %}:自定义高亮
    form.as_table:生成表格,里边会自动成成input标签
    query:查询的参数
    page.object_list:返回的查询一页数据
    result:数据对象集
    result.object:当前查询的数据对象
    page.has_previous or page.has_next:分页

    6. 高亮配置 

    # 7.高亮加载
    <style>
        span.highlighted {
            color: red;
        }
    </style>
                
    # 1.使用默认值
    {% highlight result.summary with query %}
    # 案例
    <a href="{{ result.object.get_absolute_url }}">
    {% highlight result.object.title with query %}
    </a>
                
    # 2.这里我们为 {{ result.summary }}里所有的 {{ query }} 指定了一个<div></div>标签,并且将class设置为highlight_me_please,这样就可以自己通过CSS为{{ query }}添加高亮效果了,怎么样,是不是很科学呢
    {% highlight result.summary with query html_tag "div" css_class "highlight_me_please" %}
     
    # 3.这里可以限制最终{{ result.summary }}被高亮处理后的长度
    {% highlight result.summary with query max_length 40 %}           
    
    # 5.自定义使用(后面会介绍)
    # 5.4格式
    {% myhighlight <text_block> with <query> [css_class "class_name"] [html_tag "span"] [max_length 200] [start_head True] %}
    # 5.2使用一
    {% myhighlight result.object.content with query css_class "highlighted" html_tag "span" max_length 200 start_head True %}
    # 5.3自定义二
    {% myhighlight result.object.content with query css_class "highlighted" start_head True %}        

    7.自定义

    自定义返回内容

    在app下新建一个文件名称search_views

    # 重写SearchView,实现自定义内容
    # blog/search_views.py
    from haystack.views import SearchView
    # 导入模块
    from .models import *
    
    
    class MySeachView(SearchView):
        def extra_context(self):  # 重载extra_context来添加额外的context内容
            context = super(MySeachView, self).extra_context()
            my_str = '111'
            context['my_str'] = my_str
            # print(context)
            return context
    

    修改路由

    from django.contrib import admin
    from django.urls import path, include, re_path
    from blog import search_views
    
    urlpatterns = [
        path('admin/', admin.site.urls),
        # 原生的
        # re_path(r'^search/', include('haystack.urls')),
        # 自己的
        re_path(r'^search/', search_views.MySeachView(), name='haystack_search'),
    ]

    前端使用 

    <div>
    圆明园:{{ my_str }}
    </div>

    自定义search.html模板 

    1. 保证有一个from,get请求,input标签的name=q,value=Search,

    <form method="get" action=".">
        <table>
    <tr>
    <th>
    <label for="id_q">Search:</label>
    </th>
    <td>
    <input type="search" name="q" value="不得不说" id="id_q">
    </td>
    </tr>
            <tr>
                <td>
                    <input type="submit" value="Search">
                </td>
            </tr>
        </table>
    </form>

    自定义高亮显示(原生的会省略)

    新建文件夹templatetags

    添加blog/templatetags/my_filters_and_tags.py 文件和 blog/templatetags/highlighting.py 文件,

    内容如下(源码分别位于haystack/templatetags/lighlight.py 和 haystack/utils/lighlighting.py 中):
    my_filters_and_tags.py

    # encoding: utf-8
    from __future__ import absolute_import, division, print_function, unicode_literals
     
    from django import template
    from django.conf import settings
    from django.core.exceptions import ImproperlyConfigured
    from django.utils import six
     
    from haystack.utils import importlib
     
    register = template.Library()
     
    class HighlightNode(template.Node):
        def __init__(self, text_block, query, html_tag=None, css_class=None, max_length=None, start_head=None):
            self.text_block = template.Variable(text_block)
            self.query = template.Variable(query)
            self.html_tag = html_tag
            self.css_class = css_class
            self.max_length = max_length
            self.start_head = start_head
     
            if html_tag is not None:
                self.html_tag = template.Variable(html_tag)
     
            if css_class is not None:
                self.css_class = template.Variable(css_class)
     
            if max_length is not None:
                self.max_length = template.Variable(max_length)
     
            if start_head is not None:
                self.start_head = template.Variable(start_head)
     
        def render(self, context):
            text_block = self.text_block.resolve(context)
            query = self.query.resolve(context)
            kwargs = {}
     
            if self.html_tag is not None:
                kwargs['html_tag'] = self.html_tag.resolve(context)
     
            if self.css_class is not None:
                kwargs['css_class'] = self.css_class.resolve(context)
     
            if self.max_length is not None:
                kwargs['max_length'] = self.max_length.resolve(context)
     
            if self.start_head is not None:
                kwargs['start_head'] = self.start_head.resolve(context)
     
            # Handle a user-defined highlighting function.
            if hasattr(settings, 'HAYSTACK_CUSTOM_HIGHLIGHTER') and settings.HAYSTACK_CUSTOM_HIGHLIGHTER:
                # Do the import dance.
                try:
                    path_bits = settings.HAYSTACK_CUSTOM_HIGHLIGHTER.split('.')
                    highlighter_path, highlighter_classname = '.'.join(path_bits[:-1]), path_bits[-1]
                    highlighter_module = importlib.import_module(highlighter_path)
                    highlighter_class = getattr(highlighter_module, highlighter_classname)
                except (ImportError, AttributeError) as e:
                    raise ImproperlyConfigured("The highlighter '%s' could not be imported: %s" % (settings.HAYSTACK_CUSTOM_HIGHLIGHTER, e))
            else:
                from .highlighting import Highlighter
                highlighter_class = Highlighter
     
            highlighter = highlighter_class(query, **kwargs)
            highlighted_text = highlighter.highlight(text_block)
            return highlighted_text
     
     
    @register.tag
    def myhighlight(parser, token):
        """
        Takes a block of text and highlights words from a provided query within that
        block of text. Optionally accepts arguments to provide the HTML tag to wrap
        highlighted word in, a CSS class to use with the tag and a maximum length of
        the blurb in characters.
        Syntax::
            {% highlight <text_block> with <query> [css_class "class_name"] [html_tag "span"] [max_length 200] %}
        Example::
            # Highlight summary with default behavior.
            {% highlight result.summary with request.query %}
            # Highlight summary but wrap highlighted words with a div and the
            # following CSS class.
            {% highlight result.summary with request.query html_tag "div" css_class "highlight_me_please" %}
            # Highlight summary but only show 40 characters.
            {% highlight result.summary with request.query max_length 40 %}
        """
        bits = token.split_contents()
        tag_name = bits[0]
     
        if not len(bits) % 2 == 0:
            raise template.TemplateSyntaxError(u"'%s' tag requires valid pairings arguments." % tag_name)
     
        text_block = bits[1]
     
        if len(bits) < 4:
            raise template.TemplateSyntaxError(u"'%s' tag requires an object and a query provided by 'with'." % tag_name)
     
        if bits[2] != 'with':
            raise template.TemplateSyntaxError(u"'%s' tag's second argument should be 'with'." % tag_name)
     
        query = bits[3]
     
        arg_bits = iter(bits[4:])
        kwargs = {}
     
        for bit in arg_bits:
            if bit == 'css_class':
                kwargs['css_class'] = six.next(arg_bits)
     
            if bit == 'html_tag':
                kwargs['html_tag'] = six.next(arg_bits)
     
            if bit == 'max_length':
                kwargs['max_length'] = six.next(arg_bits)
     
            if bit == 'start_head':
                kwargs['start_head'] = six.next(arg_bits)
     
        return HighlightNode(text_block, query, **kwargs)

    highlighting.py

    # encoding: utf-8
     
    from __future__ import absolute_import, division, print_function, unicode_literals
     
    from django.utils.html import strip_tags
     
     
    class Highlighter(object):
        #默认值
        css_class = 'highlighted'
        html_tag = 'span'
        max_length = 200
        start_head = False
        text_block = ''
     
        def __init__(self, query, **kwargs):
            self.query = query
     
            if 'max_length' in kwargs:
                self.max_length = int(kwargs['max_length'])
     
            if 'html_tag' in kwargs:
                self.html_tag = kwargs['html_tag']
     
            if 'css_class' in kwargs:
                self.css_class = kwargs['css_class']
     
            if 'start_head' in kwargs:
                self.start_head = kwargs['start_head']
     
            self.query_words = set([word.lower() for word in self.query.split() if not word.startswith('-')])
     
        def highlight(self, text_block):
            self.text_block = strip_tags(text_block)
            highlight_locations = self.find_highlightable_words()
            start_offset, end_offset = self.find_window(highlight_locations)
            return self.render_html(highlight_locations, start_offset, end_offset)
     
        def find_highlightable_words(self):
            # Use a set so we only do this once per unique word.
            word_positions = {}
     
            # Pre-compute the length.
            end_offset = len(self.text_block)
            lower_text_block = self.text_block.lower()
     
            for word in self.query_words:
                if not word in word_positions:
                    word_positions[word] = []
     
                start_offset = 0
     
                while start_offset < end_offset:
                    next_offset = lower_text_block.find(word, start_offset, end_offset)
     
                    # If we get a -1 out of find, it wasn't found. Bomb out and
                    # start the next word.
                    if next_offset == -1:
                        break
     
                    word_positions[word].append(next_offset)
                    start_offset = next_offset + len(word)
     
            return word_positions
     
        def find_window(self, highlight_locations):
            best_start = 0
            best_end = self.max_length
     
            # First, make sure we have words.
            if not len(highlight_locations):
                return (best_start, best_end)
     
            words_found = []
     
            # Next, make sure we found any words at all.
            for word, offset_list in highlight_locations.items():
                if len(offset_list):
                    # Add all of the locations to the list.
                    words_found.extend(offset_list)
     
            if not len(words_found):
                return (best_start, best_end)
     
            if len(words_found) == 1:
                return (words_found[0], words_found[0] + self.max_length)
     
            # Sort the list so it's in ascending order.
            words_found = sorted(words_found)
     
            # We now have a denormalized list of all positions were a word was
            # found. We'll iterate through and find the densest window we can by
            # counting the number of found offsets (-1 to fit in the window).
            highest_density = 0
     
            if words_found[:-1][0] > self.max_length:
                best_start = words_found[:-1][0]
                best_end = best_start + self.max_length
     
            for count, start in enumerate(words_found[:-1]):
                current_density = 1
     
                for end in words_found[count + 1:]:
                    if end - start < self.max_length:
                        current_density += 1
                    else:
                        current_density = 0
     
                    # Only replace if we have a bigger (not equal density) so we
                    # give deference to windows earlier in the document.
                    if current_density > highest_density:
                        best_start = start
                        best_end = start + self.max_length
                        highest_density = current_density
     
            return (best_start, best_end)
     
        def render_html(self, highlight_locations=None, start_offset=None, end_offset=None):
            # Start by chopping the block down to the proper window.
            #text_block为内容,start_offset,end_offset分别为第一个匹配query开始和按长度截断位置
            text = self.text_block[start_offset:end_offset]
     
            # Invert highlight_locations to a location -> term list
            term_list = []
     
            for term, locations in highlight_locations.items():
                term_list += [(loc - start_offset, term) for loc in locations]
     
            loc_to_term = sorted(term_list)
     
            # Prepare the highlight template
            if self.css_class:
                hl_start = '<%s class="%s">' % (self.html_tag, self.css_class)
            else:
                hl_start = '<%s>' % (self.html_tag)
     
            hl_end = '</%s>' % self.html_tag
     
            # Copy the part from the start of the string to the first match,
            # and there replace the match with a highlighted version.
            #matched_so_far最终求得为text中最后一个匹配query的结尾
            highlighted_chunk = ""
            matched_so_far = 0
            prev = 0
            prev_str = ""
     
            for cur, cur_str in loc_to_term:
                # This can be in a different case than cur_str
                actual_term = text[cur:cur + len(cur_str)]
     
                # Handle incorrect highlight_locations by first checking for the term
                if actual_term.lower() == cur_str:
                    if cur < prev + len(prev_str):
                        continue
     
                    #分别添上每个query+其后面的一部分(下一个query的前一个位置)
                    highlighted_chunk += text[prev + len(prev_str):cur] + hl_start + actual_term + hl_end
                    prev = cur
                    prev_str = cur_str
     
                    # Keep track of how far we've copied so far, for the last step
                    matched_so_far = cur + len(actual_term)
     
            # Don't forget the chunk after the last term
            #加上最后一个匹配的query后面的部分
            highlighted_chunk += text[matched_so_far:]
     
            #如果不要开头not start_head才加点
            if start_offset > 0 and not self.start_head:
                highlighted_chunk = '...%s' % highlighted_chunk
     
            if end_offset < len(self.text_block):
                highlighted_chunk = '%s...' % highlighted_chunk
     
            #可见到目前为止还不包含start_offset前面的,即第一个匹配的前面的部分(text_block[:start_offset]),如需展示(当start_head为True时)便加上
            if self.start_head:
                highlighted_chunk = self.text_block[:start_offset] + highlighted_chunk
            return highlighted_chunk

    前端使用

    <style>
        span.highlighted {
            color: red;
        }
    </style>
    
    {% load my_filters_and_tags %}
    
    
    
    {% myhighlight result.object.content with query css_class "highlighted" html_tag "span" max_length 200 start_head True %}
    

     8. 目前位置搜索已经完成,可以重建索引,同步数据,测试一下

    python manage.py rebuild_index
    

    9.jieba分词器配置

    9.1 先从python包中复制whoosh_backend.py到app中,并改名为whoosh_cn_backend.py

    文件路径:\site-packages\haystack\backends\whoosh_backend.py

     

    复制到的路径:

    9.2 对whoosh_cn_backend.py做以下修改:

    1、导入 ChineseAnalyze
    from jieba.analyse import ChineseAnalyzer
    
    2、替换schema_fields[field_class.index_fieldname] = TEXT(下的analyzer
    analyzer=ChineseAnalyzer(),
    

     9.3 在django的配置文件中,修改搜索引擎

    HAYSTACK_CONNECTIONS = {
        'default': {
            # 设置haystack的搜索引擎
            'ENGINE': 'blog.whoosh_cn_backend.WhooshEngine',
            # 'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine',
            # 设置索引文件的位置
            'PATH': os.path.join(BASE_DIR, 'whoosh_index'),
        }
    }

    10 django+django-haystack+Elasticsearch7.5+ik+mysql

    10.0 切换成es引擎,除了settings.py和把jieba换成ik,其他步骤跟上面的都一样

    如果一开始,就是奔着es+ik来的,那步骤9 jieba分词器配置 不用看,直接从步骤8跳到这里来

    10.1 安装es,ik

    基于docker安装Elasticsearch+ElasticSearch-Head+IK分词器_骑台风走的博客-CSDN博客基于docker安装Elasticsearch+ElasticSearch-Head+IK分词器https://blog.csdn.net/qq_52385631/article/details/126567059?spm=1001.2014.3001.5501

    10.2 使用ik重写es7.5引擎

    10.2.1 新建elasticsearch_ik_backend.py(在自己的app下)

    在 blog应用下新建名为 elasticsearch7_ik_backend.py 的文件,继承 Elasticsearch7SearchBackend(后端) 和 Elasticsearch7SearchEngine(搜索引擎) 并重写建立索引时的分词器设置

    from haystack.backends.elasticsearch7_backend import Elasticsearch7SearchBackend, Elasticsearch7SearchEngine
    
    """
    分析器主要有两种情况会被使用:
    第一种是插入文档时,将text类型的字段做分词然后插入倒排索引,
    第二种就是在查询时,先对要查询的text类型的输入做分词,再去倒排索引搜索
    
    如果想要让 索引 和 查询 时使用不同的分词器,ElasticSearch也是能支持的,只需要在字段上加上search_analyzer参数
    
    在索引时,只会去看字段有没有定义analyzer,有定义的话就用定义的,没定义就用ES预设的
    
    在查询时,会先去看字段有没有定义search_analyzer,如果没有定义,就去看有没有analyzer,再没有定义,才会去使用ES预设的
    """
    
    DEFAULT_FIELD_MAPPING = {
        "type": "text",
        "analyzer": "ik_max_word",
        # "analyzer": "ik_smart",
        "search_analyzer": "ik_smart"
    
    }
    
    
    class Elasticsearc7IkSearchBackend(Elasticsearch7SearchBackend):
        def __init__(self, *args, **kwargs):
            self.DEFAULT_SETTINGS['settings']['analysis']['analyzer']['ik_analyzer'] = {
                "type": "custom",
                "tokenizer": "ik_max_word",
                # "tokenizer": "ik_smart",
            }
            super(Elasticsearc7IkSearchBackend, self).__init__(*args, **kwargs)
    
    
    class Elasticsearch7IkSearchEngine(Elasticsearch7SearchEngine):
        backend = Elasticsearc7IkSearchBackend
    

     10.3 修改settings.py(切换成功)

    # es 7.x配置
    HAYSTACK_CONNECTIONS = {
        'default': {
            # 'ENGINE': 'haystack.backends.elasticsearch7_backend.Elasticsearch7SearchEngine',
            'ENGINE': 'blog.elasticsearch_ik_backend.Elasticsearch7IkSearchEngine',
            # 'URL': 'http://106.14.42.253:9200/',
            'URL': 'http://106.14.42.253:9200/',
            # elasticsearch建立的索引库的名称,一般使用项目名作为索引库
            'INDEX_NAME': 'elastic_new',
        },
    }

    10.4 重建索引,同步数据

    python manage.py rebuild_index
    

    10.5 补充

    10.5.1 未成功切换成ik

    haystack 原先加载的是 …\venv\Lib\site-packages\haystack\backends 文件夹下的 elasticsearch7_backend.py 文件,打开即可看到 elasticsearch7 引擎的默认配置 

    若用上述方法建立出来的索引字段仍使用 snowball 分词器,则将原先elasticsearch7_backend.py 文件中的 DEFAULT_FIELD_MAPPING 也修改为 ik 分词器(或许是因为版本问题)

    位置:D:\py_virtualenv\dj_ha\Lib\site-packages\haystack\backends\elasticsearch7_backend.py

    修改内容:

    DEFAULT_FIELD_MAPPING = {
        "type": "text",
        "analyzer": "ik_max_word",
        "search_analyzer": "ik_smart",
    }

    10.5.2 es6版本加入ik,重写引擎

    from haystack.backends.elasticsearch_backend import ElasticsearchSearchBackend
    from haystack.backends.elasticsearch_backend import ElasticsearchSearchEngine
    class IKSearchBackend(ElasticsearchSearchBackend):
        DEFAULT_ANALYZER = "ik_max_word" # 这里将 es 的 默认 analyzer 设置为 ik_max_word
    
        def __init__(self, connection_alias, **connection_options):
            super().__init__(connection_alias, **connection_options)
    
        def build_schema(self, fields):
            content_field_name, mapping = super(IKSearchBackend, 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"
                    ) and not 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
    
    
    class IKSearchEngine(ElasticsearchSearchEngine):
        backend = IKSearchBackend

    11.实时更新索原理:采用信号

    配置

    # 在django配置文件中,添加索引值,文章更新的时候,就会自动更新索引值
    HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'

    RealtimeSignalProcessor源码如下:

    class RealtimeSignalProcessor(BaseSignalProcessor):
        """
        Allows for observing when saves/deletes fire & automatically updates the
        search engine appropriately.
        当 检索对象出现保存或者删除的时候更新索引值。
        """
        def setup(self):
            # Naive (listen to all model saves).
            models.signals.post_save.connect(self.handle_save)
            models.signals.post_delete.connect(self.handle_delete)
         
            # Efficient would be going through all backends & collecting all models
            # being used, then hooking up signals only for those.
        def teardown(self):
            # Naive (listen to all model saves).
            models.signals.post_save.disconnect(self.handle_save)
            models.signals.post_delete.disconnect(self.handle_delete)
            # Efficient would be going through all backends & collecting all models
            # being used, then disconnecting signals only for those.
    

    本文借鉴

    Django haystack实现全文搜索 – -零 – 博客园 (cnblogs.com)
    (9条消息) django-haystack全文检索详细教程_AC_hell的博客-CSDN博客
    (9条消息) Django全文检索Haystack模块_NQ31的博客-CSDN博客_django haystack
    (9条消息) django+drf_haystack+elasticsearch_骑台风走的博客-CSDN博客

    (5条消息) Haystack 使用 Elasticsearch 建立索引时 修改为中文分词器_SevenBerry的博客-CSDN博客_elasticsearch 修改字段分词器

    (5条消息) Elasticsearch中analyzer和search_analyzer的区别_chuixue24的博客-CSDN博客

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