一：参考官方文档
1. Elasticsearch 5.4.0英文手册
https://www.elastic.co/guide/en/elasticsearch/reference/5.4/search-request-post-filter.html
2. 《Elasticsearch权威指南》中文版
https://www.elastic.co/guide/cn/elasticsearch/guide/current/_talking_to_elasticsearch.html
3. 参考文档PHP-API
https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/_quickstart.html
二：安装PHP-SDK
https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/_installation_2.html
三：Quickstart
https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/_quickstart.html