RiSearch PHP techniques for implementing multi-field search and matching degree calculation

RiSearch PHP techniques for implementing multi-field search and matching degree calculation

Introduction:
With the rapid development of the Internet, search functions occupy a large share in Web applications Its important position is also becoming more and more prominent. For users, how to accurately find the required information in massive data has become a very important requirement. For developers, how to implement efficient and accurate search functions has also become a challenge. This article will introduce how to use the RiSearch PHP library to perform multi-field searches and calculate the matching degree of search results.

1. Introduction to RiSearch
RiSearch is a full-text search engine library based on inverted index, which can index and search text. RiSearch has the following characteristics:

1. Supports multi-field search: RiSearch allows searching on multiple fields, and can set different weights for different fields according to specific needs.
2. Real-time search: RiSearch can index and search immediately as new data is received in real-time.
3. Support Chinese word segmentation: RiSearch has a built-in Chinese word segmenter, which can accurately segment Chinese words.
4. Support advanced search functions: RiSearch provides rich search functions, such as fuzzy search, range search, etc.

2. Install and configure RiSearch

1. Download and decompress the RiSearch compressed package, which can be obtained from its official website (https://github.com/riopen/RiSearch) The latest version of.
2. Copy the decompressed file to the PHP extension directory (extension_dir).

3. Add the following lines in the php.ini configuration file:

   extension=rilive.so

4. Restart the web server to make the configuration take effect.

3. Use RiSearch for multi-field search
First, we need to prepare the data set to be searched and index the data. Suppose we want to search a collection of documents, where each document contains two fields: title and content.

1. Create RiSearch index object and set fields:

   $index = new RiIndex('/path/to/index'); // 指定索引的存储路径
   $index->addField('title', 1.0); // 设置title字段的权重为1.0
   $index->addField('content', 0.5); // 设置content字段的权重为0.5

2. Index data:

   $documents = [
    ['title' => 'PHP开发', 'content' => 'PHP是一种流行的服务器端脚本语言。'],
    ['title' => 'Java开发', 'content' => 'Java是一种广泛使用的高级编程语言。'],
    // ...
   ];
   
   foreach ($documents as $document) {
    $index->addDocument($document);
   }

3. Proceed Search:

   $query = '开发'; // 搜索关键词
   
   $results = $index->search($query);
   
   foreach ($results as $result) {
    echo '标题：' . $result['title'] . ' 匹配度：' . $result['score'] . PHP_EOL;
   }

4. Calculate the matching degree of search results
RiSearch will return a matching degree (score) for each search result, and the value range of score is 0 to 1 represents the relative degree of matching. The larger the value, the higher the matching degree. RiSearch calculates the matching degree based on the weight of each field in the document and the frequency of keywords in the field. The calculation formula is as follows:

score = sum(weight * freq) / norm

Among them, weight is the weight of the field, freq is the frequency of keywords in the field, and norm is the normalization factor of the document.

The above is a detailed introduction to the techniques of using the RiSearch PHP library to implement multi-field search and matching degree calculation. By using the efficient and accurate search functions provided by RiSearch, we can provide users with a better search experience and meet different business needs. I hope this article will be helpful to everyone in the practice of using RiSearch for multi-field search.

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