ES SQL 官网资料 - 阅读有困难的加了翻译 - 我只是官网的搬运工

官网地址： https://www.elastic.co/guide/en/elasticsearch/reference/6.6/sql-overview.html

Elasticsearch SQL aims to provide a powerful yet lightweight SQL interface to Elasticsearch.

    Introduction

    Elasticsearch SQL is an X-Pack component that allows SQL-like queries to be executed in real-time against Elasticsearch. Whether using the REST interface, command-line or JDBC, any client can use SQL to search and aggregate data natively inside Elasticsearch. One can think of Elasticsearch SQL as a translator, one that understands both SQL and Elasticsearch and makes it easy to read and process data in real-time, at scale by leveraging Elasticsearch capabilities.

    Why Elasticsearch SQL ?

    Native integration

    Elasticsearch SQL is built from the ground up for Elasticsearch. Each and every query is efficiently executed against the relevant nodes according to the underlying storage.

    No external parts

    No need for additional hardware, processes, runtimes or libraries to query Elasticsearch; Elasticsearch SQL eliminates extra moving parts by running inside the Elasticsearch cluster.

    Lightweight and efficient

    Elasticsearch SQL does not abstract Elasticsearch and its search capabilities - on the contrary, it embraces and exposes SQL to allow proper full-text search, in real-time, in the same declarative, succint fashion.

 

   To start using Elasticsearch SQL, create an index with some data to experiment with:

PUT /library/book/_bulk?refresh
{"index":{"_id": "Leviathan Wakes"}}
{"name": "Leviathan Wakes", "author": "James S.A. Corey", "release_date": "2011-06-02", "page_count": 561}
{"index":{"_id": "Hyperion"}}
{"name": "Hyperion", "author": "Dan Simmons", "release_date": "1989-05-26", "page_count": 482}
{"index":{"_id": "Dune"}}
{"name": "Dune", "author": "Frank Herbert", "release_date": "1965-06-01", "page_count": 604}

    Copy as cURLView in Console 

And now you can execute SQL using the SQL REST API right away:

POST /_xpack/sql?format=txt
{
    "query": "SELECT * FROM library WHERE release_date < '2000-01-01'"
}

    Copy as cURLView in Console 

Which should return something along the lines of:

    author     |     name      |  page_count   | release_date
---------------+---------------+---------------+------------------------
Dan Simmons    |Hyperion       |482            |1989-05-26T00:00:00.000Z
Frank Herbert  |Dune           |604            |1965-06-01T00:00:00.000Z

    You can also use the SQL CLI. There is a script to start it shipped in x-pack’s bin directory:

$ ./bin/elasticsearch-sql-cli

From there you can run the same query:

sql> SELECT * FROM library WHERE release_date < '2000-01-01';
    author     |     name      |  page_count   | release_date
---------------+---------------+---------------+------------------------
Dan Simmons    |Hyperion       |482            |1989-05-26T00:00:00.000Z
Frank Herbert  |Dune           |604            |1965-06-01T00:00:00.000Z