原英文版地址: https://www.elastic.co/guide/en/elasticsearch/reference/7.7/sql-rest-columnar.html, 原文档版权归 www.elastic.co 所有
本地英文版地址: ../en/sql-rest-columnar.html
本地英文版地址: ../en/sql-rest-columnar.html
重要: 此版本不会发布额外的bug修复或文档更新。最新信息请参考 当前版本文档。
Columnar resultsedit
The most well known way of displaying the results of an SQL query result in general is the one where each individual record/document represents one line/row. For certain formats, Elasticsearch SQL can return the results in a columnar fashion: one row represents all the values of a certain column from the current page of results.
The following formats can be returned in columnar orientation: json, yaml, cbor and smile.
POST /_sql?format=json
{
"query": "SELECT * FROM library ORDER BY page_count DESC",
"fetch_size": 5,
"columnar": true
}
Which returns:
{
"columns": [
{"name": "author", "type": "text"},
{"name": "name", "type": "text"},
{"name": "page_count", "type": "short"},
{"name": "release_date", "type": "datetime"}
],
"values": [
["Peter F. Hamilton", "Vernor Vinge", "Frank Herbert", "Alastair Reynolds", "James S.A. Corey"],
["Pandora's Star", "A Fire Upon the Deep", "Dune", "Revelation Space", "Leviathan Wakes"],
[768, 613, 604, 585, 561],
["2004-03-02T00:00:00.000Z", "1992-06-01T00:00:00.000Z", "1965-06-01T00:00:00.000Z", "2000-03-15T00:00:00.000Z", "2011-06-02T00:00:00.000Z"]
],
"cursor": "sDXF1ZXJ5QW5kRmV0Y2gBAAAAAAAAAAEWWWdrRlVfSS1TbDYtcW9lc1FJNmlYdw==:BAFmBmF1dGhvcgFmBG5hbWUBZgpwYWdlX2NvdW50AWYMcmVsZWFzZV9kYXRl+v///w8="
}
Any subsequent calls using a cursor still have to contain the columnar parameter to preserve the orientation,
meaning the initial query will not remember the columnar option.
POST /_sql?format=json
{
"cursor": "sDXF1ZXJ5QW5kRmV0Y2gBAAAAAAAAAAEWWWdrRlVfSS1TbDYtcW9lc1FJNmlYdw==:BAFmBmF1dGhvcgFmBG5hbWUBZgpwYWdlX2NvdW50AWYMcmVsZWFzZV9kYXRl+v///w8=",
"columnar": true
}
Which looks like:
{
"values": [
["Dan Simmons", "Iain M. Banks", "Neal Stephenson", "Frank Herbert", "Frank Herbert"],
["Hyperion", "Consider Phlebas", "Snow Crash", "God Emperor of Dune", "Children of Dune"],
[482, 471, 470, 454, 408],
["1989-05-26T00:00:00.000Z", "1987-04-23T00:00:00.000Z", "1992-06-01T00:00:00.000Z", "1981-05-28T00:00:00.000Z", "1976-04-21T00:00:00.000Z"]
],
"cursor": "46ToAwFzQERYRjFaWEo1UVc1a1JtVjBZMmdCQUFBQUFBQUFBQUVXWjBaNlFXbzNOV0pVY21Wa1NUZDJhV2t3V2xwblp3PT3/////DwQBZgZhdXRob3IBBHRleHQAAAFmBG5hbWUBBHRleHQAAAFmCnBhZ2VfY291bnQBBGxvbmcBAAFmDHJlbGVhc2VfZGF0ZQEIZGF0ZXRpbWUBAAEP"
}