Question

是否可以在datediff中使用datepart

  SELECT   datediff (YEAR,2015 ,(datepart(YEAR,Person.DateOfBirth))) AS Exp from Person

请帮帮我

Answer 1

datediff的参数应该是日期，例如：

datediff(year, '20150101', Person.DateOfBirth)

使用年份时，请记住它跟踪年份的变化，因此不适合计算年龄，例如

select datediff(year, '20150101', '20150201')

返回0，但

select datediff(year, '20141231', '20150201')

返回1.

Answer 2

是，但形成这样......

datediff(result In(Year/Month/Day),toDate,Fromdate)

＆＃39; 2015＆＃39;在约会中是2015-01-01＆＃39;

尝试：select CAST('2015' as date)

SELECT datediff(YEAR,'2015',Person.DateOfBirth) AS Exp from Person--result in year 
SELECT datediff(Month,'2015',Person.DateOfBirth) AS Exp from Person--result in month 
SELECT datediff(Day,'2015',Person.DateOfBirth) AS Exp from Person--result in day

是否可以在datediff中使用datepart？

2 个答案: