假設有如下場景:
電表,大家都知道電表讀數並不是真正的耗電量,真正耗電量=此次讀數-上一次讀數
電表設計如下:
SQL語句如下,使用Oracle的FIRST_VALUE()和LAST_VALUE()函數實現:
SELECT DISTINCT LAST_VALUE (E_VALUE) OVER (PARTITION BY E_CODE ORDER BY E_DATE ROWS BETWEEN unbounded preceding AND unbounded following) AS LAST_TIME_VALUE, FIRST_VALUE (E_VALUE) OVER (PARTITION BY E_CODE ORDER BY E_DATE ROWS BETWEEN unbounded preceding AND unbounded following) AS FIRST_TIME_VALUE FROM TABLE_TEST
結果:
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原文鏈接:https://blog.csdn.net/rongtaoup/article/details/82253615