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DataGrid/GridView Paging and Sorting Using A DataReader

Ways to bind a DataGrid

Now most web apps simply need quick data retrieval presented to the client and again it's now good to discover that the DataGrid is not locked in with the DataSet, as we'll momentarily see.

There are some cool ways to bind a DataGrid that most people may not know about. I'll discuss two ways one could efficiently bind a DataGrid. The first really cool way to bind a DataGrid with is using a DataReader bound ArrayList , and the other way is using a standalone DataTable in conjunction with a DataView. Both will use the DataReader in getting our data, and both will have the cool paging and sorting features I mentioned as well. And, by the way, they're both cacheable, to further increase performance and scalability!

For all intents and purposes, the two methods that are going to be illustrated will be nearly identical, expect for the soon evident data creation/storage method, which is the aptly named GetDataReader subroutine listed below. The Arraylist in our example draws on the DataReader, but again in this instance to circumvent the error message above, I employ the DataReader and ArrayList to instance a new lightweight Structure Class (struct in C#) as opposed to a full fledged Class, to store our data in its properties, and this is what makes the difference in allowing you to bind a DataGrid with all it's features, instead of trying to natively bind a Datareader to a DataGrid. You can find more on Structures and Classes here - The Quick and Dirty .NET Guide to C#/VB Object-Oriented Programming. Additionally, the DataTable technique will also use the Datareader to create a new DataTable and a DataView to sort the data, and it's your typical run of the mill setup.

Notwithstanding, for brevity in this article I will discuss in detail the two aforementioned techniques solely and will not be discussing how to set up paging and sorting. For that have a look at Dynamic Column Sorting and Paging in ASP.NET for more detail. And also glance at .NET Data Caching to find out more insight on the caching methodologies discussed here.

So before we examine what the code does, I'll just list the entire code for you to have a good OnPreRender view of it, and break it down afterwards :-) We'll start off now with the ArrayList method code:

Comments

  1. 17 Jul 2009 at 10:50

    The info is really helpful to the beginers. Thanks alot it saves my alot of time. -Shailu

  2. 01 Feb 2009 at 18:11
    Hi Sohail, thanks. Now, If you're looking to squeeze out as much as you can in terms of performance I would go with the ArrayList. It would be faster with less overhead. Nothing really dramatic, rather more efficient.
  3. 30 Jan 2009 at 12:16
    Good Article. I have one specific question. I was using Dataset for aspnet 2.0 application until i realized that it is very efficient if you are thinking about performance. I have a girdview with paging feature using dataset. After reading few article i started using datareader and binding them to gridview (with Datatable). i.e. Return SqlHelper.ExecuteReader(GeneralFunctions.GetConnectionString, CommandType.Text, StrQuery) Dim dt As New DataTable dt.Load(EventsDBClient.GETALLRECORDS()) ' about 100 records Me.girdview.DataSource = dt Me.girdview.DataBind() My question is(which might not be the right one excuse me for that), considering my application will not return not more than 100records at one time. do you think datareader in combination with datatable is the right way to go about OR ArrayList/Class would be better? Thanks, Sohail
  4. 12 Jul 2007 at 15:14
    Hi all,

    What about displaying, sorting etc' data in a DataGird/GridView with a paging mechanism using a scrollbar (not a Next/Previous buttons)??

    It seems like no one has ever mention this issue.

    Can anyone please help me solve this problem.

    Regards ido









  5. 25 Nov 2006 at 08:23

    this site is really very good. i  m really a big fan of this site thanks to all

    developerfusion team

     

    jitendra negi

     

  6. 03 Nov 2006 at 09:29

    Dimitrios thanks for the informative article. I have picked your code apart and tried out a few variants of your sample code which I am looking to implement into some of my web apps.

    I tried a code sample in a web page that used “Data Grid Paging Using a Data Reader Bound Array List” – no caching or dynamic sorting.

    This method still reads all the data even though a small fraction is only displayed on the page. This works well but when I blew the table up to 100,000 records (I was using MS Access in this experiment) it slowed down somewhat. Admittedly it was substantially faster than a similar sample of code using a dataset on the same database (as expected).

     

    My question is;

     

    Is there any way that straight forward data reader + data grid paging can be implemented in such a way that it will only get the records from the database that the webapp actually displays on the page? Any suggestions, directions or web links would be appreciated.

     

  7. 25 Oct 2006 at 21:37

    I'm working on an app that implements a structure and stores a recordset in an ArrayList based upon the example outlined here.  I used the same to bind to a DataGrid and it worked out so well, I thought it might be a better solution that moving back and forth through a DataSet to perform some simple though numerous calculations. 

    In order to perform these calcs, I have to compare elements of the array checking for duplicates on some columns and then just comparing other elements to strings utilizing IndexOf and LastIndexOf.  Unfortunately I haven't been able to get it to work.  On another site I read that those 2 methods use Object.Equals and as the array contains structure objects, I need to override the Equals function.  That route has been just as unsuccessful. 

    The code below generates an that the index is out of range on the line that assigns the array item to 'last' because the LastIndexOf search returns -1.  Thing is the stored procedure I use to retrieve the recordset guarantees that there would be a match on first.account.  Can anyone point me in the right direction?

    Public Overrides Function Equals(ByVal obj As Object) As Boolean

    If obj Is Nothing Or Not Me.GetType() Is obj.GetType() Then

    Return False

    End If

    Dim d As duplicates = CType(obj, duplicates)

    Return Me.account = d.account

    End Function

     

    'Errant code below

    conn.Open()

    Dim reader As SqlDataReader = cmd.ExecuteReader()

    If reader.HasRows Then

    'Create array to hold entries for accounts tracked more than once per LOB

    Dim arrResults As New ArrayList

    Dim dupEntries As New duplicates

    While reader.Read

    With arrResults

    .Add(

    New duplicates(reader.GetValue(0), reader.GetValue(1), reader.GetValue(2), _

    reader.GetValue(3), reader.GetValue(4), reader.GetValue(5), reader.GetValue(6), _

    reader.GetValue(7), reader.GetValue(8), reader.GetValue(9), reader.GetValue(10), _

    reader.GetValue(11), reader.GetValue(12), reader.GetValue(13), reader.GetValue(14)))

    End With

    End While

    reader.Close()

    Dim first As duplicates

    Dim last As duplicates

    Dim i As Integer

    For i = 0 To arrResults.Count - 1

    first =

    CType(arrResults.Item(i), duplicates)

    Trace.Warn(arrResults.LastIndexOf(first.account))

    last = arrResults.Item(arrResults.LastIndexOf(first.account))

    Trace.Warn(

    "first date" & first.tDate)

    Trace.Warn(

    "last date " & last.tDate)

    Next

    End If

     

  8. 28 Aug 2006 at 18:57
    I've been searching around, but haven't been able to figure out how to access the individual values.  For example, how would I determine CompanyName for a particular row?
  9. 18 Jul 2006 at 16:02

    Yeah thanks. No, it does absolutely work, regardless, and even though the "AllowCustomPaging" property isn't part of the Gridview, it does not affect it, as I just copied the code from the article and it ran perfectly. The Gridview simply ignores it, whether set to "True" or "False"

    I would check and make sure it's not something else you may have modified.

    Hope this helps

  10. 17 Jul 2006 at 00:24

    Good article overall.  But the Gridview version cannot work.  One problem is it shows the following property:

    AllowCustomPaging="False"

    that is not available in Gridview.



     

     

  11. 30 May 2006 at 11:30

    Hello...

    Can anybody plis post the C# version?

    Thx in advance...

  12. 28 Apr 2006 at 17:48

    Sup everyone...

    I have a datagrid and I want to implement a button that will simulate the datagrid scroll down click button. What events do I need to handle? How to make my datagrid rows to scroll once my button is pressed?

     

  13. 23 Apr 2006 at 09:21

    Hello

    The DataReaders read one-way data As I undesrtand you dynamically bind your Oracle Database to your Datagird. Try to convert oracleDataReader  to DataView. DataViews can be red 2 way and they are Compatible with AllowPaging=true

    I have recently sent a Control to Asp.Net I think it is in the proccessing stage that Control converts OdbcDataReader to DataView below is the open code for you to give you an idea. You must apply the same logic to your Oracle Reader

    Good Luck,

    Baris ERGUN

    www.thecoreopsis.com

    public static DataView ConvertToDataView(OdbcDataReader setToCheck, string tableName)

    {

    DataTable dataReaderTable = new DataTable(tableName);

    try

    {

    for(int h=0;h<setToCheck.FieldCount;h++)

    {

    DataColumn temp = new DataColumn(setToCheck.GetName(h),setToCheck.GetFieldType(h));

    dataReaderTable.Columns.Add(temp);

    }

    while(setToCheck.Read())

    {

    DataRow dr = dataReaderTable.NewRow();

    for(int g=0;g<setToCheck.FieldCount;g++)

    {

    drGift [G] = setToCheck.GetValue(setToCheck.GetOrdinal(setToCheck.GetName(g)));

    }

    dataReaderTable.Rows.Add(dr);

    }

    return dataReaderTable.DefaultView;

    }

    catch

    {

    return null;

    }

    }

  14. 01 Jan 1999 at 00:00

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Dimitrios Markatos Dimitrios, or Jimmy as his friends call him, is a .NET developer/architect who specializes in Microsoft Technologies for creating high-performance and scalable data-driven enterprise Web and deskto...

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