Home / Community & Support / Developer Productivity Tools Forums / OpenAccess ORM > OpenAccess ORM Free Edition > LINQ - LEFT JOIN

• Neagoe

  Posted on Mar 15, 2011 (permalink)

  var Query = from antete_facturi in ZdbContext.AnteteFacturis
                          join adrese_livrare in ZdbContext.AdreseLivrares on new { Idadresalivrare = antete_facturi.IdAdresaLivrare } equals new { Idadresalivrare = adrese_livrare.Id } into adrese_livrare_join
                          from adrese_livrare in adrese_livrare_join.DefaultIfEmpty()
                          select new
                          {
                              Adresalivrare = adrese_livrare.AdresaLivrare,
                              antete_facturi.IdPartener,
                              antete_facturi.NrFactura,
                              antete_facturi.DataFactura
                          };
  
  Previous linq query work perfect in dbml model, in OA result is null.
  I try to do an evaluation of the product before I buy it, if you have a suggestion to the above problem, please post a reply.
  Best regards,
     Adrian Neagoe

  Reply

• Petko_I Petko_I

  Posted on Mar 21, 2011 (permalink)

  Hello Neagoe,
  
  Unfortunately, this LINQ scenario with DefaultIfEmpty() is not fully supported yet by OpenAccess. We are working towards improving our LINQ support and this scenario will be one of the first things that we will address. A workaround would be to retrieve the matching joined records in one query and invoke a second query to retrieve the hanging records from the left outer join. Let's consider the following example - we have Orders served by Employees and not every employee has served an order. To get those employees we may first find the rest of the employees who have participated in an order and exclude them from the overall set of the employees:
  

  IList<int?> employeeServedOrders = context.Orders.Select(x => x.EmployeeID).Distinct().ToList();

  var query = from employee in context.Employees

           where !employeeServedOrders.Contains(employee.EmployeeID)

           select employee;

  
  We do hope you will find the provided information useful. We will be working on making your example running without extra queries. Should you have further questions, feel free to contact us.
  
  Best wishes,
  Petko_I
  the Telerik team

  Vote for the 7 Telerik products at the 2011 Great Indian Developer Awards!

  Reply

• Karlo

  Posted on Feb 8, 2012 (permalink)

  Hi Petko_I,
  
  How can your solution be done when using openaccesslinqdatasource?

  Reply

• Damyan Bogoev Damyan Bogoev

  Posted on Feb 10, 2012 (permalink)

  Hello Karlo,

  I have prepared a sample application which demonstrates how to achieve that goal using OpenAccessLInqDataSource.
  Hope that helps.
  
  All the best,
  Damyan Bogoev
  the Telerik team

  Want to use Telerik OpenAccess with SQL Azure? Download the trial version today. 

  Attached files

  • SampleApplication.zip

  Reply

Back to Top

Home / Community & Support / Developer Productivity Tools Forums / OpenAccess ORM > OpenAccess ORM Free Edition > LINQ - LEFT JOIN