Using entity query OrderBy clause in include table

Question

Hi all,

I have a problem when building query having a OrderBy clause in include table:

I have 2 table: Vendor, VendorContacts with association: 1->*

1 Vendor has many VendorContacts. I need to show a vendor contact called Primary Contact in Vendor gridview

I want to building query for sorting function for First Name conlum in grid view :

I try this:

ObjectContext.Vendors.Include(v => v.VendorContacts).OrderBy(f => f.VendorContacts.FirstOrDefault(i => i.IsPrimaryContact).FirstName)

but it doesn't work, 

 Does any one have ideal for this,

Thanks you very much

Answer 1

Try:

ObjectContext.Vendors.Include("VendorContracts")
   .Where(v => v.VendorContacts.IsPrimaryContact == true);

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Bob - www.crowcoder.com

Answer 2

It is basically joined and orderby.

Take a look on this:http://www.codeimagine.com/2012/02/how-to-use-join-and-orderby-in-linq-to.html

chanmm

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chanmm

Answer 3

Hello,

>>ObjectContext.Vendors.Include(v => v.VendorContacts).OrderBy(f => f.VendorContacts.FirstOrDefault(i => i.IsPrimaryContact).FirstName)

The OrderBy in the case will only work for properties in Vendors.

If you want to order by sub properties, we have to use LINQ lambda expression.

var result = (from school in db.Schools

                              join student in db.Students

                              on school.schoolId equals student.schoolId

                              where student.IsPrimaryStudent == true

                              orderby student.studentname descending

                              select new { school.schoolId, school.schoolname, student.studentId, student.studentname }).ToList();

The result will be:

Regards.

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