Question

Best way to handle dynamic datagrid columns from a pivot table.

Asked by: acadalzo

I want to display the results of a pivot table in a datagrid.  I have defined the static columns in the <Columns> section as bound columns.  Since I don't know what the pivoted columns are going to be (they are data dependent) I have to dynamically add them in the code before doing the data binding.  That works ok, but on postback is where it gets ugly.  What I have to do in the Page_Init is recreate the dynamic columns because they won't be preserved in the postback.  Unless they are  recreated in the Page_Init event, the sort event will not fire when the header of one of the "pivot" (i.e. dynamic) columns is clicked.  This means I have to save those column names in a Session variable, so I know what I need to recreate on the postback.  That handles the problem with sorting on a pivot column.  If instead of doing a sort, the user changes any of the criteria, I get the new set of data and I transform it into a new pivot table.  Now I have to delete all of the pivot columns in the datagrid from the previous request.    It seems that there are a whole lot of issues to deal with for dynamically-created columns.  Is there an easier way?  Am I missing something here?  Thanks.

This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2005-06-06 at 07:34:15ID21448130
Tags

datagrid

,

dynamic

,

pivot

,

columns

Topic

Programming for ASP.NET

Participating Experts
3
Points
500
Comments
7

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. Transform - Pivot statement
    TRANSFORM Sum(Table1.Value) AS SumOfValue SELECT Table1.Year FROM Table1 GROUP BY Table1.Year PIVOT Table1.DestCountry; This works like I want to. The problem is, Table1.DestCountry is a number. In another table, I have the information I need to replace the number with th...
  2. pivot table
    hi, Is there a way to make dynamic pivot table using ASP? thx
  3. Pivot/transform and Union
    I have a problem with pivot/transform work with union, here is the sql statement: transform sum([sales amount]) as amount select class from table1 group by class pivot year <----(part A) union transform sum([sales amount]) as amount select class from table2 group by...

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: b1xml2Posted on 2005-06-06 at 07:50:37ID: 14153685

can you instead change the underlying source, and set AutoGenerateColumns to  true and hook into the ItemCreated and ItemDataBound to further finetune the display. What I mean by this is you have your original source of data which you transform by code to another dataset with the columns in the datatable determined by the original data, thereby having a datatable that can be plugged straight into a DataGrid. This way, you deal purely with the data and let the DataGrid do its thing.

 

by: acadalzoPosted on 2005-06-06 at 07:58:49ID: 14153763

Sorry, the columns are not 'bound columns' as I stated in the question, but they are mostly hyperlink columns.  Only one column, the "Total" column is a bound column, so I don't think the AutoGenerateColumns would work for me.

 

by: saleekPosted on 2005-06-06 at 09:30:29ID: 14154770

Shouldn't be a problem. My datagrid does something similar and all I do is re-build columns in the viewstate event like so:

I use a property to maintain a bool value of whether the columns have been added:

Private Property DynamicColumnAdded() As Boolean
        Get
            If ViewState("ColumnAdded") Is Nothing Then
                Return False
            Else
                Return True
            End If
        End Get
        Set(ByVal Value As Boolean)
            ViewState("ColumnAdded") = Value
        End Set
    End Property

Then in viewstate event:

Protected Overrides Sub LoadViewState(ByVal savedState As Object) MyBase.LoadViewState(savedState)
        If Me.DynamicColumnAdded Then
            Me.CreateTemps()
        End If
End Sub

After I create the columns I set: DynamicColumnAdded = True

Also, I clear the columns like so before building template columns: Datagrid1.Columns.Clear()


regards,

KS

 

by: acadalzoPosted on 2005-06-08 at 13:51:48ID: 14174584

How do you know the names of the dynamic columns that you have to re-create in your CreateTemps(). Are you saving the names of the dynamic columns somewhere? Are you putting them in a Session variable maybe or using the SaveViewState()? Mine vary because of the nature of the pivot table.  If the postback is due to a SortCommand, then I have to know the name of the columns so that I can recreate it in the grid in order for the SortCommand Event handler to fire.

 

by: shivam2kPosted on 2005-06-22 at 00:39:06ID: 14273131

i too had the same problem

In Page_Load Event  changed from

If Not Page.IsPostBack Then
   BindGrid()
End If

to

BindGrid()

in BindGrid()

while adding new bound columns check


If dgResults.Columns.Count = 0 Then
     dgResults.AutoGenerateColumns = False
     dgResults.AllowSorting = True
     dgResults.Width.Percentage(100)
     For loopCount = 0 To columnsList.Count - 1
          resultGridColumn = New BoundColumn
          resultGridColumn.DataField = columnsList(loopCount)
          resultGridColumn.HeaderText = columnsList(loopCount)
          resultGridColumn.SortExpression = columnsList(loopCount)
          dgResults.Columns.Add(resultGridColumn)
     Next
End If

this sorted out the problem

sort event was fired after this

 

by: acadalzoPosted on 2005-07-01 at 08:41:56ID: 14348815

Does your columnsList change each time?  Where does the columnsList come from?  Is it in ViewState?

 

by: shivam2kPosted on 2005-07-01 at 20:18:09ID: 14352575

the column list was dynamic and so were based on xml - for each xml node id it was different columns and different tables

i didnt maintain in the viewstate, as the column were based on xml and xml id

and i call the bind grid in page load, its generated again, obvious the column list is not going to change during sort event.

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...