I am trying to sort by a child entity. I am using version 2.6. I've set up the code this way:

 EntityCollection<ScheduleTemplateEntity> schedules = new EntityCollection<ScheduleTemplateEntity>(new ScheduleTemplateEntityFactory());
            RelationPredicateBucket bucket = new RelationPredicateBucket();
            bucket.Relations.Add(ScheduleTemplateEntity.Relations.ScheduleDetailEntityUsingCompanyIdScheduleId);
            bucket.Relations.Add(ScheduleDetailEntity.Relations.DaysOfWeekEntityUsingCompanyIdDayOfWeekId);
            SortExpression sort = new SortExpression(DaysOfWeekFields.SortOrder | SortOperator.Ascending);
            adapter.FetchEntityCollection(schedules, null, 0, sort);
            return schedules;

When the query runs, it throws this error:

SD.LLBLGen.Pro.ORMSupportClasses.ORMQueryExecutionException was unhandled



Message="An exception was caught during the execution of a retrieval query: Correlation name 'DaysOfWeek' not found. Check InnerException, QueryExecuted and Parameters of this exception to examine the cause of this exception."



Source="SD.LLBLGen.Pro.ORMSupportClasses.NET20"



RuntimeBuild="08042008"



RuntimeVersion="2.6.0.0"



QueryExecuted="\r\n\tQuery: SELECT [DBA].[ScheduleTemplate].[CompanyID] AS CompanyId, [DBA].[ScheduleTemplate].[ScheduleTemplateID] AS ScheduleTemplateId, 

[DBA].[ScheduleTemplate].[ScheduleTemplateName], [DBA].[ScheduleTemplate].[AdjustToFixedSchedule], [DBA].[ScheduleTemplate].[ArriveEarlyWithinLength], [DBA].[ScheduleTemplate].[ArriveLateWithinLength] FROM [DBA].[ScheduleTemplate] ORDER BY [DBA].[DaysOfWeek].[SortOrder] ASC\r\n"

I am hoping that this is something simple that I have missed.

Thanks for your help!

Allen

My apologies. I realized that I had forgotten to include the RelationPredicate bucket in my call to adapter. I have fixed that:

EntityCollection<ScheduleTemplateEntity> schedules = new EntityCollection<ScheduleTemplateEntity>(new ScheduleTemplateEntityFactory());

            IPrefetchPath2 prefetchPath = new PrefetchPath2((int)EntityType.ScheduleTemplateEntity);
            prefetchPath.Add(ScheduleTemplateEntity.PrefetchPathScheduleDetail).SubPath.Add(ScheduleDetailEntity.PrefetchPathDaysOfWeek);

            RelationPredicateBucket bucket = new RelationPredicateBucket();
            bucket.Relations.Add(ScheduleTemplateEntity.Relations.ScheduleDetailEntityUsingCompanyIdScheduleId);
            bucket.Relations.Add(ScheduleDetailEntity.Relations.DaysOfWeekEntityUsingCompanyIdDayOfWeekId);
            
            SortExpression sort = new SortExpression(DaysOfWeekFields.SortOrder | SortOperator.Ascending);
            
            adapter.FetchEntityCollection(schedules, bucket, 0, sort, prefetchPath);
            
            return schedules;

And now the query executes but the collection isn't in the order that I expect (ordered by DayOfWeekFields.SortOrder). How can I get the collection sorted by the desired column?

Thanks,

Allen

As you pass the sort expression variable to the root fetch, the root fetch is ordered by its sub-sub-related entity (DaysOfWeek). You are fetching a graph with three levels. What level do you want to sort?

To sort on a prefetchPath, use the .Add overload that accept a PredicateExpression.

Hope helpful

Thank you for the response, but you lost me a little. In my example, for each Entity called ScheduleTemplate, there would be 7 ScheduleDetail entities that each have a single DayOfWeek entity. We need to get the ScheduleDetail records in order by the DayOfWeek.SortOrder field.

You say to use a prefetchPath that accepts a PredicateExpression, but don't I need a SortExpression? I thought PredicateExpression was for filtering? Did I misunderstand this?

Can you give me a quick example?

Thanks,

Allen

We need to get the ScheduleDetail records in order by the DayOfWeek.SortOrder field.

As Daelmo said you need to pass the relation and sortExpression to the prefetchPath, as follows.

            EntityCollection<ScheduleTemplateEntity> schedules = new EntityCollection<ScheduleTemplateEntity>(new ScheduleTemplateEntityFactory());

            IRelationCollection relations = new RelationCollection();
            relations.Add(ScheduleDetailEntity.Relations.DaysOfWeekEntityUsingCompanyIdDayOfWeekId);
            
            SortExpression sort = new SortExpression(DaysOfWeekFields.SortOrder | SortOperator.Ascending);

            IPrefetchPath2 prefetchPath = new PrefetchPath2((int)EntityType.ScheduleTemplateEntity);
            prefetchPath.Add(ScheduleTemplateEntity.PrefetchPathScheduleDetail, 0, null, relations, sort);//.SubPath.Add(ScheduleDetailEntity.PrefetchPathDaysOfWeek);
            
            adapter.FetchEntityCollection(schedules, null, 0, null, prefetchPath);          
            return schedules;

Note: Add the SubPath if you want to fetch the DaysOfWeek as well.

Thank you very much for the reply. This helps. I've been going through the help and all of the examples and I think that one things I find confusing is that the examples use different syntax wihout really an explanation of why. For example, you used the following code

IRelationCollection relations = new RelationCollection();
            relations.Add(ScheduleDetailEntity.Relations.DaysOfWeekEntityUsingCompanyIdDayOfWeekId);

but in the help, the Relations are created this way:

RelationPredicateBucket bucket = new RelationPredicateBucket();
bucket.Relations.Add(CustomerEntity.Relations.OrderEntityUsingCustomerID);
bucket.Relations.Add(OrderEntity.Relations.OrderDetailsEntityUsingOrderID);
bucket.Relations.Add(OrderDetailsEntity.Relations.ProductEntityUsingProductID);
bucket.Relations.Add(ProductEntity.Relations.SupplierEntityUsingSupplierID);

What is the difference between the two? What reasons would I use one or the other? Are they functionally the same?

Thanks,

Allen

You just need to pay attention to the Reference manual and what parameters are accepted by different methods.

Using the Adapter model, most fetch methods accepts a RelationPredicateBucket, which is just a container or a bucket (hence the name) which holds a PredicateExpression and a RelationCollection objects.

These 2 are separated in the overloads of the PrefetchPath.Add() method. That's why I created a RelationCollection and passed it to the Add() method, instead of creating a RelationPredicate bucket.

I think V.S. intellisense mighthelp you figure out which paramter is needed for each method. (and for each overload).