Monthly Archives: April 2012

T-SQL String DeAggregate (Split, Ungroup) in SQL Server

A while back I posted a simple way to aggregate strings in SQL Server, but what if your task is opposite – you have a character-separated string values in your fields and you need to slice them into separate rows? Consider following scenario, you have a table:

CREATE TABLE #Employees (Country varchar(50), FirstNames varchar(50))

INSERT INTO #Employees(Country,FirstNames) 
	 VALUES ('UK','Anne,Michael,Robert,Steven')
INSERT INTO #Employees(Country,FirstNames)
     VALUES ('USA','Andrew,Janet,Laura,Margaret,Nancy')

SELECT Country, FirstNames FROM #Employees

That looks like this

Country  FirstNames
UK       Anne,Michael,Robert,Steven
USA      Andrew,Janet,Laura,Margaret,Nancy

and now you need to split FirstNames so that every FirstName is displayed on separate row. Continue reading →

SSRS viewer doesn’t work on IIS7 64bit

If you’re developing an ASP.NET application that utilizes Microsoft’s SSRS ReportViewer control, you may experience a weird behavior while trying to use it on 64 bit version of IIS7 (Windows Server 2008 or Windows 7) – nothing is displayed in the main report area and even icons, such as Print, Export aren’t rendering.

One possible cause for this – your application is using Application Pool with 32bit mode enabled. If so – disable it or switch to a different application pool. Chances are this will fix the above issue.

WHDG: Correctly detect Async Callback

When using Infragistics WebHierarchicalDataGrid often there’s a need to detect grid’s async callback (for example we need to rebind the grid if it performs AJAX paging or expanding children). For flat WebDataGrid it was suggested to use grid’s RunBot.IsCallback property:

If xMyGrid.RunBot.IsCallback Then
   'Perform some operations for grid's async callback
End If

Now, WHDG also has RunBot.IsCallback property, but the above code always returns False for it. I know I’ve seen this before – a situation where a property doesn’t work on WHDG control itself, but works on the WHDG’s GridView object. Sensing a pattern I modified the code above for WHDG:

If xMyGrid.GridView.RunBot.IsCallback Then
   'Perform some operations for grid's async callback
End If

And bingo! Now Async callback is detected correctly.

UPDATE 4/27/2012: Turned out the above method doesn’t always work either. (To Infragistics stuff, if anybody happened to read this: The scenario above happens with WHDG in manual load on demand mode when grid’s RowIslandPopulating event is handled and ContainerGrid is created on demand and bound to data retrieved from the Database). The above method works when rows of the top level expanded (xMyGrid.GridView.RunBot.IsCallback is True) but fails if child rows are expanded to show grandchildren (in that case xMyGrid.GridView.RunBot.IsCallback is False).

We need another more reliable way to detect callback, no matter what caused it. And we can do that by checking HTTP Request. If it’s an Infragistics callback it will have a Form parameter with key like "__IGCallback************". So the code to always detect the callback correctly is:

If Request.Form.AllKeys.Any(Function(S As String) S IsNot Nothing AndAlso S.StartsWith("__IGCallback")) Then
   'Perform some operations for grid's async callback
End If

WebDataTree returns multiple selected nodes in single-select mode

This could be a bug in Infragistics WebDataTree control or it could be a very specific scenario (maybe it’s even by design, I don’t know) but here’s a weird behavior that I encountered. Using following code in WebDataTree’s event handler (oh and by the way, tree control is in a single-select mode):

Protected Sub xMyTree_SelectionChanged(ByVal sender As Object, ByVal e As NavigationControls.DataTreeSelectionEventArgs) Handles MyTree.SelectionChanged
   if e.NewSelectedNodes(0).Text = "Some Value"
      'do something with newly selected tree node
   end if
End Sub

I intended to use newly selected node to perform some operations. To my surprise e.NewSelectedNodes(0) referred to previously selected node (despite the name of the property) and newly selected value were located in e.NewSelectedNodes(1)! So the quick workaround was to use slightly modified code:

Protected Sub xMyTree_SelectionChanged(ByVal sender As Object, ByVal e As NavigationControls.DataTreeSelectionEventArgs) Handles MyTree.SelectionChanged
   if e.NewSelectedNodes(e.NewSelectedNodes.Count-1).Text = "Some Value"
      'do something with newly selected tree node
   end if
End Sub

This way it will always get latest selected node and the solution is universal. If the bug described above occurs – code will grab e.NewSelectedNodes(1) (because Count = 2). If the tree behaves as expected – code will get grab e.NewSelectedNodes(0) (because Count = 1)

iOS is ported to Kindle Fire!

Apple iOS running on Amazon Kindle Fire
Those coding wizards from XDJ-Developers have done it again! After years of supplying us with huge amounts of amazing custom ROMs for even huger amount of Android devices they performed yet another miracle which is akin to splitting the atom, since it separates what was formerly considered inseparable: Apple hardware and software.

They ported iOS to Kindle Fire.

Don’t expect it to be the latest version though (iOS 6 as of time of this post) for that you will have to wait couple hours. For now be content with 5.1 – it’s well worth it. iOS 5.1 runs very smoothly on Kindle Fire, in tests pretty much everything lives up to high standards we used to expect from Apple, just about only app that wouldn’t run is Fruit Slice, I can’t imagine why.

Being an early beta build, it still has a few quirks. For example sometimes, if you launch iTunes, you end up in Amazon MP3 Store and on very rare occasions in some place called “Tower Records” (must be phantom growing pains) but XDJ-Developers are hard at work to eradicate those.

So rejoice closet Apple fans! No longer you have to pretend to like cupcakes, donuts, eclairs, froyo, gingerbread, honeycombs, ice cream sandwiches and the rest of those high calory desserts. Time for a healthy diet of fruit!