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| # 数据查询 |
| |
| 数据查询有如下几种类型 |
| |
| * 原始数据查询 |
| * 聚合查询 |
| * 降采样查询 |
| * 单点补空值查询 |
| * 最新数据查询 |
| * 按设备对齐查询 |
| * 降采样补空值查询 |
| * 按时间倒序查询 |
| |
| 为了实现以上几种查询，IoTDB 查询引擎中设计了针对单个时间序列的基础查询组件，在此基础上，实现了多种查询功能。 |
| |
| ## 相关文档 |
| |
| * [查询基础介绍](../DataQuery/QueryFundamentals.md) |
| * [基础查询组件](../DataQuery/SeriesReader.md) |
| * [原始数据查询](../DataQuery/RawDataQuery.md) |
| * [聚合查询](../DataQuery/AggregationQuery.md) |
| * [降采样查询](../DataQuery/GroupByQuery.md) |
| * [最近时间戳查询](../DataQuery/LastQuery.md) |
| * [按设备对齐查询](../DataQuery/AlignByDeviceQuery.md) |
| * [空值填充](../DataQuery/FillFunction.md) |
| * [降采样补空值查询](../DataQuery/GroupByFillQuery.md) |
| * [按时间倒序查询](../DataQuery/OrderByTimeQuery.md) |
