Better way to summarize data about stop times?

Question

This question is close to this:

http://stackoverflow.com/questions/2947963/find-the-period-of-over-speed

Here's my table:

  Longtitude    Latitude    Velocity    Time
102           401            40      2010-06-01 10:22:34.000
103           403            50      2010-06-01 10:40:00.000
104           405             0      2010-06-01 11:00:03.000
104           405             0      2010-06-01 11:10:05.000
105           406            35      2010-06-01 11:15:30.000
106           403            60      2010-06-01 11:20:00.000
108           404            70      2010-06-01 11:30:05.000
109           405             0      2010-06-01 11:35:00.000
109           405             0      2010-06-01 11:40:00.000
105           407            40      2010-06-01 11:50:00.000
104           406            30      2010-06-01 12:00:00.000
101           409            50      2010-06-01 12:05:30.000
104           405             0      2010-06-01 11:05:30.000

I want to summarize times when vehicle had stopped (velocity = 0), include: it had stopped since "when" to "when" in how much minutes, how many times it stopped and how much time it stopped.

I wrote this query to do it:

select longtitude, latitude, MIN(time), MAX(time), DATEDIFF(minute, MIN(Time), MAX(time))
as Timespan from table_1 where velocity = 0 group by longtitude,latitude

select DATEDIFF(minute, MIN(Time), MAX(time)) as minute into #temp3
 from table_1 where velocity = 0 group by longtitude,latitude

select COUNT(*) as [number]from #temp
select SUM(minute) as [totaltime] from #temp3

drop table #temp

This query return:

longtitude  latitude    (No column name)    (No column name)    Timespan
    104 405 2010-06-01 11:00:03.000 2010-06-01 11:10:05.000 10
    109 405 2010-06-01 11:35:00.000 2010-06-01 11:40:00.000 5

number
2

totaltime
15

You can see, it works fine, but I really don't like the #temp table. Is there anyway to query this without use a temp table?

Thank you.

Answer 1

You can't nest aggregates in SQL Server (e.g. SUM(DATEDIFF(minute, MIN(Time), MAX(time))) but can use a derived table in preference to a temporary table.

SELECT SUM(minute) FROM
(
select DATEDIFF(minute, MIN(Time), MAX(time)) as minute 
 from table_1 where velocity = 0 group by longtitude,latitude
) derived