Help with an Aggregate Calculation Sum( DateTime ) in a DataTable

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edcha - 18 Apr 2008 00:03 GMT

I am trying to use the following Aggregate Calculation.
string time = trabajadoresTable.Compute ( "Sum(DateTime)" ,
"") .ToString();

I need to sum the hours in a column with type DateTime.
If they be numbers this work good
"trabajadoresTable.Compute("Sum(pago)", "")"
But with the type DateTime's in a column make me the following error

In the System.Data.DataException was generated the error:
Invalid use of Aggregate Calculation Sum( ) and the type DateTime.

how I sum the hours in one column if it the type is DateTime

Thanks

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Marc Gravell - 18 Apr 2008 08:19 GMT

loop and accumalate...

int hours = 0;
foreach(blah row in records)
{
hours += row.DateField.Hour;
}

If you have LINQ you can do it inline:

int hours = records.Sum(row => row.DateField.Hour);

Marc

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edcha - 20 Apr 2008 20:55 GMT

I don't have a Linq

Only it can be done for loop and accumalate...

Thanks

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