Question

我需要在字段差异（-20.00）中'今天'（200）和'今天-4'（220）之间的小时数之间的差异。有人如何帮助我为此构建查询？

Today        Date      Hours    Difference
10/29/2014  11/15/2014  220  
10/30/2014  11/15/2014  220  
10/31/2014  11/15/2014  200  
11/1/2014   11/15/2014  200  
11/2/2014   11/15/2014  200     -20.00

Answer 1

DECLARE Time1 int;
DECLARE Time2 int;
DECLARE Result int;

SET Time1 = (SELECT Hours From TBL_NAME WHERE Today = '10/29/2014')
SET Time2 = (SELECT Hours From TBL_NAME WHERE Today = '11/2/2014')
SET Result = Time1 - Time2;

UPDATE TBL_NAME SET Difference = Result WHERE Today = 'Your Field Value'

Answer 2

UPDATE TABLE 
SET Difference=((SELECT HOURS FROM TABLE WHERE TODAY='10/29/2014)'
-(SELECT HOURS FROM TABLE WHERE TODAY='11/2/2014'))
WHERE TODAY = '11/2/2014'

来自同一列的两个值之间的差异

2 个答案: