sql - 单列数据差异

Question

我试图找到单列数据中的差异，即差异将是

Column C
date 2 (1/2/12) would check the difference from date 1 (1/1/12)
date 3 (1/3/12) would check the difference from date 2 (1/2/12)
date 4 (1/4/12) would check the difference from date 3 (1/3/12)

我想我可以创建另外两列 Date days -1 和 amount 然后显示差异

Column A<date>  Column B<Amount> Column C <Difference>
1/1/12            550             -150
1/2/12            400              300
1/3/12            700             -200
1/4/12            500

谢谢你的帮助

Answer 1

您可以使用 LEAD解析函数

SELECT  "Column A", 
        "Column B",
        (LEAD("Column B", 1) OVER (ORDER BY "Column A") - "Column B") AS "Difference"
FROM    TableName

SQLFiddle Demo

其他

LAG and LEAD Analytic Functions