Question

我当前的派生数据集如下所示

--------------------------------------------------------------------
|      Type_ID |  component  |    timestamp             |  status  |
-------------------------------------------------------------------
|       52     |     G1      |Aug 25, 2014 9:10:47.0 AM |   IN     |
|       53     |     G1      |Aug 27, 2014 11:11:29.0 AM|   OUT    |
|       58     |     G1      |Aug 27, 2014 11:11:29.0 AM|   OUT    |
|       53     |     G1      |Aug 27, 2014 11:11:29.0 AM|   OUT    |
|              |     G1      |Aug 27, 2014 11:11:29.0 AM|   GEN    | 
|       52     |     G2      |Aug 28, 2014 11:11:29.0 AM|   IN     |
|       52     |     G1      |Aug 29, 2014 11:11:29.0 AM|   IN     |
|              |     G2      |Aug 29, 2014 12:11:29.0 AM|   GEN    |
--------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------------
|      Type_ID |  component  |    timestamp             |  status  |  Type_Id | component | timestamp                | status |
-------------------------------------------------------------------------------------------------------------------------------
|              |     G1      |Aug 27, 2014 11:11:29.0 AM |   GEN   |    52    |    G1     |Aug 25, 2014 9:10:47.0 AM | IN    |
|              |     G2      |Aug 29, 2014 12:11:29.0 AM |   GEN   |    52    |     G2    |Aug 28, 2014 11:11:29.0 AM|   IN    |

所以根据状态IN，我想获得TYPE_ID''的先前记录，尝试使用LAG，但无法根据STATUS = IN动态获取以前的记录，

数据库：SAP HANA， SQL会很有帮助

Answer 1

SELECT *, LAG(TYPE_ID) OVER (ORDER BY TIMESTAMP), LAG(STATUS) OVER (ORDER BY TIMESTAMP), LAG(TIMESTAMP) OVER (ORDER BY TIMESTAMP) FROM TAB
WHERE STATUS IN ('IN')
ORDER BY TIMESTAMP;

首先，我们将消除所有不需要的记录，并在新结果集上使用滞后。

以前的记录根据具体情况而定

1 个答案: