将表达式转换为数据类型日期时间的算术溢出错误

Question

I am trying to get days difference between 2 days and I am getting below error. Could any one please help

CONVERT(DECIMAL,((dbo.convertToUnixTime(GETDATE())-p.CREATEDDATE)))

Msg 8115, Level 16, State 2, Line 79

Arithmetic overflow error converting expression to data type datetime.

Answer 1

使用日期函数：

SELECT DATEDIFF(day,GETDATE(),p.CREATEDATE)

Answer 2

datediff() always return an integer value, expressed in the unit your are giving as first argument.

If you want something accurate, you can compute the date difference in seconds, then use artithmetics to convert to a number of days:

datediff(second, p.createdate, getdate()) / 60.0 / 60 / 24

Answer 3

If you want fractional days, then you can take the difference in another unit, say seconds, and divide:

SELECT DATEDIFF(second, p.CREATEDATE, GETDATE()) / (24.0 * 60 * 60)

Note that for DATEDIFF() the older date goes first. I assume p.CREATEDATE is in the past and you want a positive number.

If you are dealing with dates far in the past or the future, you might want to use minute rather than second or alternatively DATEDIFF_BIG() .