列式结果

通常情况下，展示 SQL 查询结果最广为人知的方式是每个独立的记录/文档代表单独的一行。对于某些格式，Elasticsearch SQL 可以以列式方式返回结果：每一行代表当前结果页中某一特定列的所有值。

以下格式支持以列式返回：json、yaml、cbor 和 smile。

						POST /_sql?format=json
					{
  "query": "SELECT * FROM library ORDER BY page_count DESC",
  "fetch_size": 5,
  "columnar": true
}
		
	

		{
  "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="
}
		
	

使用 cursor 的任何后续调用仍然必须包含 columnar 参数以保持列式返回，这意味着初始查询不会记住列式选项。

						POST /_sql?format=json
					{
  "cursor": "sDXF1ZXJ5QW5kRmV0Y2gBAAAAAAAAAAEWWWdrRlVfSS1TbDYtcW9lc1FJNmlYdw==:BAFmBmF1dGhvcgFmBG5hbWUBZgpwYWdlX2NvdW50AWYMcmVsZWFzZV9kYXRl+v///w8=",
  "columnar": true
}
		
	

其效果如下

		{
  "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"
}
		
	