Sum aggregate on field of type TimeSpan

[andieje]

Hi

Is it possible to perform a SUM aggregate on a field of type TimeSpan? When I try it I get an error: 'Invalid usage of aggregate function SUM and type: Timespan'

thanks

[andieje]

Hi

I would really appreciate it if someone from tech support could look at this question as I notice other questions posted after this one have already been answered.

Many thanks in advance

[Princy]

Hi,

A  suggestion would be to store the Timespan in seconds with type as integer  in the database. This way you will be able to calculate the total number of seconds using the Aggregate. Then you can convert the value to datetime and then format it  to display in hours and minutes using the following code :

new DateTime(timeSpan.Ticks).ToString("HH:mm:ss")


Thanks,
Princy

[Thuc Nguyen]

I'm having the same problem with Andieje. This is the greatest answer if someone give a solutions.

To Princy: your solution does not work on my case, i'm using ASP.Net tags to explain the Aggregate

<telerik:GridGroupByField FieldName="SpentTime" HeaderText="Total spent time" Aggregate="Sum" />

Thanks,
Thuc

[andieje]

Dear Thuc

There is no 'built in' answer to the problem that I am aware of. There are 2 ways around it that i know of

1) As Princy said, create an extra field in your database that has type Integer and stores the time in seconds. You can have this as a hidden column in your grid, let the radgrid calculate the aggregate for you and then display this calculation in the footer of another field

<telerik:GridBoundColumn HeaderText="Seconds" Visible="false" DataField="TimeInSecondsFromLastPoint" Aggregate="SUM" FooterAggregateFormatString="{0}"></telerik:GridBoundColumn>
 <telerik:GridBoundColumn HeaderText="Time From Last Point" DataField="TimeFromLastPoint">
</telerik:GridBoundColumn>
 in item data bound

If TypeOf e.Item Is GridFooterItem Then
Dim ts As New TimeSpan(0, 0, Integer.Parse(footerItem("TimeInSecondsFromLastPoint").Text))

footerItem("TimeFromLastPoint").Text = String.Format("Total time: {0: hh:mm:ss}", ts)

If you can't change the database naturally this solution won't be any use and you will have to go with option 2 i think.
 
2)calculate the aggregate manually in the item databound event by keeping a running total of the column.

Hope this helps
andrea

[Fernando]

Hi, I'm using MVC(CSHTML) how can aply this solution for a razor envoriment ?

Thanks!