Question

How Do I "nest" DataRelation.GetChildRows

Asked by: BriCrowe

What is the most efficient method to use datarelations to obtain the childrows going down more than one level.  For example assuming I have the ubiquitous Customer/Order/Product schema and assuming that I have established the datarelations between Customer-Order and Order-Product.  How would i obtain all of the Product records for a given customer?

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
2007-01-25 at 10:50:52ID22136931
Tags

datarelation

Topic

Microsoft Visual Basic.Net

Participating Experts
1
Points
500
Comments
5

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. DataRelation
    Can someone please help me with creating Data Relations in ASP.NET? Here is my scenario. I want to fill a dataset with 2 results using 2 dataAdapters. And I keep getting an error on one line. It makes no sense to me. I have looked at examples till I am blue, now red in t...
  2. DataRelation type matching problem?
    I have a dataset that is used to collect order information before submission. It begins as an empty dataset, and the user can add multiple people, with multiple products. THE SETUP: Schema Table Person(ID, ...) Table Orders(ID, PersonID, ...) The code that I am using for t...
  3. DataRelation: How to do it?
    Problem: I am migrating from ASP to ASP.NET (finally) and want to transfer my ADO SHAPE constructs to using DataRelation instead. I haven't been able to find any examples of how to do a DataRelation with two (or more) tables in a single database. Setup: I'll just give a b...
  4. Serializing a DataRelation
    Hi, An object within my application holds a reference to a System.Data.DataRelation object. When I try to serialize my object, I get the following message: ********************************************************************** An unhandled exception of type 'System.Runtim...

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: vbturboPosted on 2007-01-25 at 12:29:43ID: 18399052

Hi BriCrowe

I think this is what you are looking for


Dim customerOrdersRelation As DataRelation = _
   customerOrders.Relations.Add("CustOrders", _
   customerOrders.Tables("Customers").Columns("CustomerID"), _
   customerOrders.Tables("Orders").Columns("CustomerID"))

Dim orderDetailRelation As DataRelation = _
   customerOrders.Relations.Add("OrderDetail", _
   customerOrders.Tables("Orders").Columns("OrderID"), _
   customerOrders.Tables("OrderDetails").Columns("OrderID"), False)

Dim orderProductRelation As DataRelation = _
   customerOrders.Relations.Add("OrderProducts", _
   customerOrders.Tables("Products").Columns("ProductID"), _
   customerOrders.Tables("OrderDetails").Columns("ProductID"))

Dim custRow, orderRow, detailRow As DataRow

For Each custRow In customerOrders.Tables("Customers").Rows
    Console.WriteLine("Customer ID:" & custRow("CustomerID").ToString())

    For Each orderRow In custRow.GetChildRows(customerOrdersRelation)
        Console.WriteLine("  Order ID: " & orderRow("OrderID").ToString())
        Console.WriteLine(vbTab & "Order Date: " & _
          orderRow("OrderDate").ToString())

        For Each detailRow In orderRow.GetChildRows(orderDetailRelation)
            Console.WriteLine(vbTab & "   Product: " & _
              detailRow.GetParentRow(orderProductRelation) _
              ("ProductName").ToString())
            Console.WriteLine(vbTab & "  Quantity: " & _
              detailRow("Quantity").ToString())
        Next
    Next
Next

http://msdn2.microsoft.com/en-us/library/d6s958d6.aspx

vbturbo

 

by: BriCrowePosted on 2007-01-25 at 12:40:37ID: 18399162

What I really need to do is get the records into a dataset of some kind that I can work with like an array of datarows or a datatable/dataview or something.  I guess I could create an array of datarows the size of "product" and then use the inner loop to add each of the product rows to that array.  In my schema I don't need to worry about creating duplicate rows in the array.  Any other ideas?

 

by: vbturboPosted on 2007-01-25 at 12:55:20ID: 18399290

Well

I made something similar to what you are asking, if you modify this to your own data then here is routine that collect's a child's table data into a array

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim i As Integer = 0

        Dim tmptbl As New DataTable
        Dim dr As DataRow
        Dim dv As New DataView(tmptbl)

        tmptbl.Columns.Add("CompanyName", GetType(System.String))
        tmptbl.Columns.Add("Total_no_off_orders", GetType(System.Int32))
        'tmptbl.Columns.Add("Total_order_value", GetType(System.String))

        ' Dim an array of datarows to hold the child records.
        Dim drarray() As DataRow
        'Look up all rows in the company table
        For Each companyRow In ds.Tables("Company").Rows
            'Select the first(row)  the company table and get its belonging child data
            drarray = ds.Tables("Company").Rows(i).GetChildRows("relCompanyOrders")
            ' Check weather a company has childrows ( if it has any orders)
            'For Each orderRow In companyRow.GetChildRows("relCompanyOrders")
            If drarray.Length() <> 0 Then

                dr = tmptbl.NewRow()
                dr(0) = drarray(0).Item(0).ToString()
                dr(1) = drarray.Length()
                tmptbl.Rows.Add(dr)

            End If
            i += 1
        Next
        grdOrders.DataSource = dv
    End Sub

Hope this helps

vbturbo

 

by: BriCrowePosted on 2007-01-26 at 15:59:23ID: 18408381

I ended up using a variation of your last suggestion.  I have posted the code below for the sake of completeness.  I still have some testing to validate the logic but I think it'll work.  I may have to copy the datarows instead of just adding them to the new table.

thank you for your help

Private Function GetFieldElements(ByVal rowField As DataRow) As DataTable

            Dim dtFieldProcElem As DataTable = _dsFD.Tables("ProcessedElement").Clone
            Dim rowElements As DataRow()
            Dim rowElement As DataRow
            Dim rowProcElems As DataRow()
            Dim rowProcElem As DataRow

            rowElements = rowField.GetChildRows("FK_Element_Field")
            For Each rowElement In rowElements
                  rowProcElems = rowElement.GetChildRows("FK_ProcElem_Element")
                  For Each rowProcElem In rowProcElems
                        dtFieldProcElem.Rows.Add(rowProcElem)
                  Next
            Next

            Return dtFieldProcElem
      End Function

 

by: vbturboPosted on 2007-01-27 at 00:26:12ID: 18409409

Just a notice to your preliminary question

<<How would i obtain all of the Product records for a given customer?

Take in to consideration- that you can have a costumer that doesn't have any orders, this i think  should be one of the validating rules.

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...