DevForce Community Forum : Query Single Entity http://www.ideablade.com/forum/ This is an XML content feed of; DevForce Community Forum : DevForce 2010 : Query Single Entity Mon, 13 Apr 2026 19:48:13 -700 Mon, 16 May 2011 07:19:28 -700 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 9.69 360 www.ideablade.com/forum/RSS_post_feed.asp?TID=2676 DevForce Community Forum http://www.ideablade.com/forum/forum_images/IdeaBlade_logo_tm.png http://www.ideablade.com/forum/ Query Single Entity : That worked. Thanks. http://www.ideablade.com/forum/forum_posts.asp?TID=2676&PID=10696#10696 Author: Randar
Subject: 2676
Posted: 16-May-2011 at 7:19am

That worked.  Thanks.]]> Mon, 16 May 2011 07:19:28 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2676&PID=10696#10696 Query Single Entity : Hi Randar, Try .First()... http://www.ideablade.com/forum/forum_posts.asp?TID=2676&PID=10681#10681 Author: sbelini
Subject: 2676
Posted: 13-May-2011 at 10:52am

Hi Randar,
 
Try .First() or .FirstOrDefault() instead of .ToList().
 
Note that if you are working asynchronously (i.e. Silverlight) you will need to use .AsScalarAsync()
 
var queryOp = _entityManager.GLAccountTypes
.Where(gla => gla.ID == ID)
.AsScalarAsync()
.First();
 
Also have in mind that in this case you will need to wait for the callback to be able to retrieve the result (i.e. queryOp does not hold the result)
 
You will find more information about executing scalar queries async in the DevForce Resource Center.
In the DevForce Resource Center you will also find valuable information about querying.
 
Silvio.


Edited by sbelini - 13-May-2011 at 10:55am]]> Fri, 13 May 2011 10:52:11 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2676&PID=10681#10681 Query Single Entity : I am completely new to DevForce,... http://www.ideablade.com/forum/forum_posts.asp?TID=2676&PID=10679#10679 Author: Randar
Subject: 2676
Posted: 13-May-2011 at 10:03am

I am completely new to DevForce, so bear with me.

Simple question.  What is the best practice for getting a single entity, based on a primary key, in this case ID.  Everything in DF seems to get back a collection and then you have to get the first item in the collection.  Is there a shortcut for getting a single entity?  Here is what I am using right now:

Dim emg As EntityManager_GL = New EntityManager_GL()
Dim atQuery = From accountType In emg.GLAccountTypes
              Where accountType.ID = ID
              Select accountType

Dim itemList = atQuery.ToList() ' TODO: Is there a better way?

If (Not itemList Is Nothing And itemList.Count > 0) Then
    Dim item = itemList(0) ' Get the first item in the list

    ' Map it to the current record
    With item
        m_ID = .ID
        m_CompanyID = .CompanyID
        m_Description = .Description
    End With
End If

p.s. I haven' tested this code because I am having issues with my web service.  But that just seems to be my environment.

]]> Fri, 13 May 2011 10:03:01 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2676&PID=10679#10679