Take 1 inside GroupBy in Linq

Question

I have a query that returns the number of records.

Example:

• Date is February 26th, then 10 records are returned to this date.
• Date is February 27th, then 15 records are returned for this date.

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I used the following query:

 var sData = vehicle.GsmDeviceLogs
                    .Where(gs => gs.Speed > zeroSpeed && !gs.DigitalInputLevel1)
                    .OrderBy(gs => gs.DateTimeOfLog)
                    .ToList();

Now I just want to get the first record for each date. i.e.

• Record date February 26th - 1.
• Record date February 27th - 1.

Answer 1

You answered in your question, share, and then select the first. Technically, you translate it to linq as follows:

var sData = vehicle.GsmDeviceLogs
              .Where(gs => gs.Speed > zeroSpeed && !gs.DigitalInputLevel1)
              .OrderBy(gs => gs.DateTimeOfLog)
              .GroupBy(gs => gs.DateTimeOfLog)
              .Select(gs => gs.First())
              .ToList();

Answer 2

DateTimeOfLog.Date ( DateTime, ), Select, :

var data = logs.Where( ... )
               .GroupBy( l => l.DateTimeOfLog.Date )
               .Select( g => new { Date = g.Key, Log = g.First() } );

( , , )