New Posts New Posts RSS Feed: Dynamic Group By and Count
  FAQ FAQ  Forum Search   Calendar   Register Register  Login Login

Dynamic Group By and Count
 Post Reply Post Reply
Author
  Share Topic Share Topic  Topic Search Topic Search  Topic Options Topic Options
BringerOD View Drop Down
DevForce MVP
DevForce MVP
Avatar

Joined: 27-Aug-2010
Location: USA
Posts: 35 		Post Options Post Options   Quote BringerOD Quote  Post ReplyReply Direct Link To This Post Topic: Dynamic Group By and Count
    Posted: 15-Sep-2011 at 8:23pm
That looks like it would do it.
 
I did not think to add a select field of "Count()".
 
Thanks
Back to Top
DenisK View Drop Down
IdeaBlade
IdeaBlade


Joined: 25-Aug-2010
Posts: 715 		Post Options Post Options   Quote DenisK Quote  Post ReplyReply Direct Link To This Post Posted: 15-Sep-2011 at 8:16pm
Hi Bryan;

Is this the type of query that you want to do dynamically?

query.GroupBy(g => g.CategoryID).Select(s => new { Name = s.Key, Total = s.Count() });

if so, this is how you would do it,

var groupBySelector = new AnonymousProjectionSelector().Combine("CategoryID");
var selectSelector = new ProjectionSelector("Key", "Name").Combine("Count()", "Total");

var q0 = query.GroupBy(groupBySelector).Select(selectSelector);


Edited by DenisK - 15-Sep-2011 at 8:26pm
Back to Top
BringerOD View Drop Down
DevForce MVP
DevForce MVP
Avatar

Joined: 27-Aug-2010
Location: USA
Posts: 35 		Post Options Post Options   Quote BringerOD Quote  Post ReplyReply Direct Link To This Post Posted: 15-Sep-2011 at 3:28pm

I figured out a way to do it using this

http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx

It’s a way to do linq queries dynamically.

var result = query.GroupBy(“FieldToGroup”,"it").Select("new(Key as Name, Count() as Total)");

Bryan
Back to Top
BringerOD View Drop Down
DevForce MVP
DevForce MVP
Avatar

Joined: 27-Aug-2010
Location: USA
Posts: 35 		Post Options Post Options   Quote BringerOD Quote  Post ReplyReply Direct Link To This Post Posted: 15-Sep-2011 at 9:41am
Does anyone know how to get a groupby count from a dynamic query?  I can group by a field, I just can't get it's count without pulling all the records down.   I just want the group field and how many there are.

This works, but only returns the key.
var selector = new AnonymousProjectionSelector().Combine("Key");


This does not.  I was only guessing anyway.
var selector = new AnonymousProjectionSelector().Combine("Key").Combine("Key.Count","Count");


Code

      public void ReadDistinctValuesAndCounts(object sender, QueryGroupsEventArgs e)
      {
         var query = BuildWhereClause(e.CollectionView, e.GroupPath, _baseQuery);
         query = BuildSortClause(e.CollectionView, query);
         var groupByField = e.ChildGroupPropertyName;
         var groupBy = new ProjectionSelector(groupByField);
   
var selector = new AnonymousProjectionSelector().Combine("Key");
         ITypedEntityQuery groupByQuery = query.GroupBy(groupBy).Select(selector);
         
         var result = groupByQuery.Execute();

       }
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down