linqtosql，timespan，aggregates ...这是可以做到的吗？

Question

这可以用linqtosql来完成吗？

SELECT City, SUM(DATEDIFF(minute,StartDate,Completed)) AS Downtime
FROM Incidents
GROUP BY City

Answer 1

using System.Data.Linq.SqlClient;

db.Incidents
  .GroupBy(i => i.City)
  .Select(g => new
  {
    City = g.Key,
    DownTime = g.Sum(i => SqlMethods.DateDiffMinute(i.StartDate, i.Completed))
  });

Answer 2

是。您必须使用SqlMethods类。

http://msdn.microsoft.com/en-us/library/bb882657.aspx