>>Hi Rob,
>>
>>This doesn't seem to work as is
>>
>>

>>  if (resourceEvent)                              
>>                  {
>>                      // Remove instructors who don't have anything planned
>>                      var query = dtInstructors.AsEnumerable().Where(c => dtAllScheduled.AsEnumerable().Any(b =>  1 == b.Field<Byte>("layer") 
>>                                          && true==b.Field<Boolean>("schdassign") && c.Field<String>("instr_id")== b.Field<String>("resource_id")
>>                                          ));
>>                      query.CopyToDataTable(dtInstructors, LoadOption.OverwriteChanges);
>>                  }

>>
>>My dtInstructors has rows but dtAllScheduled does not.
>>
>>After the query I am supposed to get 0 rows in the dtInstructors but it seems to be the same table as it was before the query. Do you see how can I adjust the code to get the query "overwrite" my original table?
>>
>>Thanks.
>
>Is it throwing an InvalidOperationException that is being caught elsewhere? See the conditions for that exception at http://msdn.microsoft.com/en-us/library/bb359707(v=vs.110).aspx

Update.

I figured this out with the following code:

               DataTable dtInstructorsAll = this.GetDataSet().Tables[0];
               DataTable dtInstructors;

               if (dtInstructorsAll.Rows.Count > 0)
               {
                  DateTime minDate = Functions.Smallest<DateTime>((DateTime)bRow.StartTime, preferenceStartTime);
                  DateTime maxDate = Functions.Largest<DateTime>((DateTime)bRow.EndTime, preferenceEndTime);

                  DateRange range = new DateRange(minDate, maxDate);

                  // GetPvtSortedResources doesn't not use instructor type where condition while GetPvtSortedSchedule does use it
                  DataTable dtAllScheduled = this.GetAllScheduled(sqlCommand, range, (resourceOnly) ? "" : instructorTypeWhere, resourceEvent);
                  Logging.LogFormat(4, "Number of eligible bookings returned in csrAllSched: {0}", dtAllScheduled.Rows.Count);

                  if (resourceEvent)                              
                  {
                      // Remove instructors who don't have anything planned
                      dtInstructors = dtInstructorsAll.Clone();
                      var query = dtInstructorsAll.AsEnumerable().Where(c => dtAllScheduled.AsEnumerable().Any(b =>  1 == b.Field<Byte>("layer") 
                                          && true==b.Field<Boolean>("schdassign") && c.Field<String>("instr_id")== b.Field<String>("resource_id")
                                          ));
                      query.CopyToDataTable(dtInstructors, LoadOption.OverwriteChanges);
                  }
                      else
                  {
                      dtInstructors = dtInstructorsAll.Copy();
                  }

So, I originally create a different table and then either copy or clone and CopyToDataTable depending on my condition.

Does it sound like an OK solution?