//fetch all instances for a particular job that finished in the last 30 days
void Main()
{
	using (var session = Scheduler.Connect(".", LoginAuthenticationType.Windows, "", ""))
	{
		using (var context = session.NewDataContext())
		{
			//fetch the job we want to report on
			var job=context.GetJob("My Job");
			
			InstanceQueryParameters queryParameters = new InstanceQueryParameters()
			{
				FetchOptions = ObjectFetchOptions.FullFetch // Use FullFetch because we are also getting LogMessages. Using StubsOnly is much slower.
			};

			//query the history for this job only
			queryParameters.TargetObjects.Add(job.OID);
			
			
			//look for instances within the last 30 days
			queryParameters.EndTimestamp=DateTime.Now;
			queryParameters.StartTimestamp=queryParameters.StartTimestamp.Value.Subtract(TimeSpan.FromDays(30));
			
			//only include instances that have finished execution
			queryParameters.Statuses.AddRange(JobStatusHelpers.FinalStatuses);
			
			//sort by Instance ID
			queryParameters.SortOrder.Add(InstanceQueryParameters.HistorySortOrder.InstanceIDDescending);
			
			//get the history
			var history=context.GetJobHistory(queryParameters);

			if (history != null)
			{
				foreach (var h in history)
				{
					Console.WriteLine($"{h.JobName} instance {h.InstanceID}");
					
					foreach(var message in h.LogMessages)
					{
						//do something with log messages if you want.	
					}
                }

			}
		}
	}
}

//fetch the most recent 5 completed instances for a particular job
void Main()
{
	using (var session = Scheduler.Connect(".", LoginAuthenticationType.Windows, "", ""))
	{
		using (var context = session.NewDataContext())
		{
			//fetch the job we want to report on
			var job=context.GetJob("My Job");
			
			InstanceQueryParameters queryParameters = new InstanceQueryParameters()
			{
				FetchOptions = ObjectFetchOptions.FullFetch // Use FullFetch because we are also getting LogMessages. Using StubsOnly is much slower.
			};

			//query the history for this job only
			queryParameters.TargetObjects.Add(job.OID);
			
			//only include instances that have finished execution
			queryParameters.Statuses.AddRange(JobStatusHelpers.FinalStatuses);
			
			//sort by Instance ID
			queryParameters.SortOrder.Add(InstanceQueryParameters.HistorySortOrder.InstanceIDDescending);
			
			//only fetch 5 instances. Since we are sorting by instance ID (descending), this will be the most recent 5 that
			//meet the other criteria
			queryParameters.PageSize=5;
			queryParameters.PageNumber=1;
			
			//get the history
			var history=context.GetJobHistory(queryParameters);

			if (history != null)
			{
				foreach (var h in history)
				{
					Console.WriteLine($"{h.JobName} instance {h.InstanceID}");
					
					foreach(var message in h.LogMessages)
					{
						//do something with log messages if you want.	
					}
                }

			}
		}

	}
}

//fetch all instances in the last 30 days for all jobs
void Main()
{
	using (var session = Scheduler.Connect(".", LoginAuthenticationType.Windows, "", ""))
	{
		using (var context = session.NewDataContext())
		{
			InstanceQueryParameters queryParameters = new InstanceQueryParameters()
			{
				FetchOptions = ObjectFetchOptions.FullFetch // Use FullFetch because we are also getting LogMessages. Using StubsOnly is much slower.
			};

			//Specify the RootGroup as the target to look at all jobs (this tells it to look at the root group, all child groups and contained jobs)
			queryParameters.TargetObjects.Add(WellKnownOIDs.RootGroup);
			
			
			//look for instances within the last 30 days
			queryParameters.EndTimestamp=DateTime.Now;
			queryParameters.StartTimestamp=queryParameters.StartTimestamp.Value.Subtract(TimeSpan.FromDays(30));
			
			//only include instances that have finished execution
			queryParameters.Statuses.AddRange(JobStatusHelpers.FinalStatuses);

			//sort by Instance ID
			queryParameters.SortOrder.Add(InstanceQueryParameters.HistorySortOrder.InstanceIDDescending);
			queryParameters.PageSize = 100;

			for(int i=1;;i++)
			{
				//if there are a lot of jobs running, 30 days of history may be too much for one request.
				//request the instances in sets of 100
				queryParameters.PageNumber=i;   //increment page number each call

				//get the history
				var history = context.GetJobHistory(queryParameters);

				if (history != null)
				{
					foreach (var h in history)
					{
						Console.WriteLine($"{h.JobName} instance {h.InstanceID}");

						foreach (var message in h.LogMessages)
						{
							//do something with log messages if you want.	
						}
					}
				}

				if(history.Count < queryParameters.PageSize)
				{
					//if the method returned fewer items than requested, there are no more items
					break;
				}
				else
				{
					//there are more items to return. Continue the loop.	
				}

			}
		}
	}
}