sql - mssql 2008 datediff with minutes -

sql - mssql 2008 datediff with minutes -

i using :

declare @startdate datetime2 = '08:00:00.000'; declare @enddate datetime2 = '08:04:21.000'; select datediff(minute, @startdate, @enddate) minute;

and output min : 4

but when input below:

declare @startdate datetime2 = '08:00:00.000'; declare @enddate datetime2 = '07:59:21.000'; select datediff(minute, @startdate, @enddate) minute;

then output : -1

so dont want output : -1 . must blank output

thank

you can utilize case statement apply logic such if @startdate greater @enddate null else datediff

select case when @startdate > @endate null else datediff(minute, @startdate, @endate) end

sql .net sql-server sql-server-2008