druid-docs-cn/querying/timeboundaryquery.md

50 lines
1.7 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!-- toc -->
<script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<ins class="adsbygoogle"
style="display:block; text-align:center;"
data-ad-layout="in-article"
data-ad-format="fluid"
data-ad-client="ca-pub-8828078415045620"
data-ad-slot="7586680510"></ins>
<script>
(adsbygoogle = window.adsbygoogle || []).push({});
</script>
## TimeBoundary查询
> [!WARNING]
> Apache Druid支持两种查询语言 [Druid SQL](druidsql.md) 和 [原生查询](makeNativeQueries.md)。该文档描述了仅仅在原生查询中的一种查询方式。
时间边界查询返回数据集的最早和最新数据点。语法是:
```json
{
"queryType" : "timeBoundary",
"dataSource": "sample_datasource",
"bound" : < "maxTime" | "minTime" > # optional, defaults to returning both timestamps if not set
"filter" : { "type": "and", "fields": [<filter>, <filter>, ...] } # optional
}
```
时间边界查询有3个主要部分
| 属性 | 描述 | 是否必须 |
|-|-|-|
| `queryType` | 该字符串始终为"search", Druid根据该字段来确定如何执行该查询 | 是 |
| `dataSource` | 要查询的数据源, 类似于关系型数据库的表。 可以通过 [数据源](datasource.md) 来查看更多信息| 是 |
| `bound` | 可选,设置为 `maxTime``minTime` 仅返回最新或最早的时间戳。如果未设置,则默认为返回两者 | 否 |
| `filter` | 参考 [Filters](filters.md) | 否 |
| `context` | 参见 [查询上下文](query-context.md) | 否 |
结果的格式为:
```json
[ {
"timestamp" : "2013-05-09T18:24:00.000Z",
"result" : {
"minTime" : "2013-05-09T18:24:00.000Z",
"maxTime" : "2013-05-09T18:37:00.000Z"
}
} ]
```