我需要比较2个日期，并返回2个小数位之间的天数。

例如：

比较时

SubmittedDate = 2012-02-29 07:02:55.000

FirstCall = 2012-02-29 12:12:19.000

这是5个小时的时差。所以我会退还0.2天

我试过了：

CAST(DATEDIFF(Hour, SubmittedDate, FirstCall)/30.0 AS DECIMAL(5,2)) As HoursBeforeFirstCall
CAST(DATEDIFF(Day, SubmittedDate, FirstCall) AS DECIMAL(5,2)) As HoursBeforeFirstCall

似乎没有任何工作。