Sorting a datagrid

trekmp · February 23rd, 2004, 09:03 AM

is there a way to get a datagrid to sort without having to requery the database again.

I'm new to .NET and would be grateful for any assistance. Full examples would be very useful for me

Many thanks

Thanks for any help provided

planoie · February 23rd, 2004, 12:08 PM

The data listing controls in .NET do not provide sorting capabilities. Some do provide a property to indicated what the current sort expression is. However, you must query the data again.

Peter
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Work smarter, not harder.

mike_remember · September 24th, 2004, 02:45 AM

Hi Friends

Can you give me in simple way the steps to sort a datagrid in asp.net using vb.net.

Thanks
Mike

mehdi62b · September 24th, 2004, 06:56 AM

Quote:

quote:Originally posted by trekmp
is there a way to get a datagrid to sort without having to requery the database again.

yes,you can save your DataView as global(put it in Cache or use a static global object)then just work on its Sort property and assign your DataView to grid's DataSource and bind your grid

Quote:

quote:Originally posted by Mike
Can you give me in simple way the steps to sort a datagrid in asp.net using vb.net.

Have a look at this example(it queries the database in every Page_Load)

Code:

<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<Script Runat="Server">

Dim dvwProducts As DataView

Sub Page_Load
  Dim conNorthwind As SqlConnection
  Dim dadProducts As SqlDataAdapter
  Dim dstProducts As DataSet

  ' Create Products DataSet
  dstProducts = New DataSet()
  conNorthwind = New SqlConnection( "Server=localhost;UID=sa;PWD=secret;Database=Northwind" )
  dadProducts = New SqlDataAdapter( "Select * From Products", conNorthwind )
  dadProducts.Fill( dstProducts, "Products" )

  ' Create default DataView
  dvwProducts = dstProducts.Tables( "Products" ).DefaultView()

  ' Bind to datagrid
  dgrdProducts.DataSource = dstProducts
  dgrdProducts.DataBind()
End Sub

Sub dgrdProducts_SortCommand( s As Object, e As DataGridSortCommandEventArgs )
  ' Sort DataView
  dvwProducts.Sort = e.SortExpression

  ' Rebind to DataGrid
  dgrdProducts.DataSource = dvwProducts
  dgrdProducts.DataBind()
End Sub
</Script>

<html>
<head><title>SortDataView.aspx</title></head>
<body>

<form Runat="Server">
<asp:DataGrid
  ID="dgrdProducts"
  AllowSorting="True"
  OnSortCommand="dgrdProducts_SortCommand"
  Runat="Server" />
</form>

</body>
</html>

--------------------------------------------
Mehdi.:)

mike_remember · September 28th, 2004, 03:42 AM

Hi

Can you tell me what exact we mean by sorting a datagrid. Why I ask this is coz when I used the commands mentioned, nothing happened, I only had the option to click the columns in a datagrid.

Please help as this is very important. If possible, can you provide me right from the scratch how to sort a datagrid & what does it mean.

Hope you all understand as this is urgent.

Thanks
Mike

planoie · September 28th, 2004, 01:15 PM

Is Mehdi's example not enough? All of the necessary parts are there.

mehdi62b · September 29th, 2004, 08:40 AM

sorting a datagrid means that we want to sort all rows according to
especial column(s)
when you set AllowSorting to true,you can sort your grid
according to the column you click,
(just for more info,you can sort your grid according to more than one column
for example like this: yourDataView.Sort="Column1 ASC,Column2 ASC";
that means if Column1 includes some rows with equal values they will be sorted
according to Column2).

--------------------------------------------
Mehdi.:)

mehdi62b · December 18th, 2004, 06:56 AM

Hi again,
above example sorts a grid but there is also a better way(in most cases),
we could save all datasource to cache then use that instead of connecting to datasource every time there is a request for new sortition ...
see below example(just has a few changes from above example)

Code:

<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<Script Runat="Server">

Sub Page_Load
  If Not IsPostBack Then
    ' Bind to datagrid
    dgrdProducts.DataSource = GetProducts()
    dgrdProducts.DataBind()
  End If
End Sub

Function GetProducts() As DataView
  Dim dstProducts As DataSet
  Dim conNorthwind As SqlConnection
  Dim dadProducts As SqlDataAdapter
  Dim dvwProducts As DataView

  dvwProducts = Cache( "Products" )
  If dvwProducts Is Nothing Then
    dstProducts = New DataSet()
    conNorthwind = New SqlConnection( "Server=localhost;UID=sa;PWD=secret;Database=Northwind" )
    dadProducts = New SqlDataAdapter( "Select * from Products", conNorthwind )
    dadProducts.Fill( dstProducts, "Products" )
    dvwProducts = dstProducts.Tables( "Products" ).DefaultView()
    Cache( "Products" ) = dvwProducts
  End If
  Return dvwProducts
End Function

Sub dgrdProducts_SortCommand( s As Object, e As DataGridSortCommandEventArgs )
  Dim dvwProducts As DataView

  ' Sort DataView
  dvwProducts = GetProducts()
  dvwProducts.Sort = e.SortExpression

  ' Rebind to DataGrid
  dgrdProducts.DataSource = dvwProducts
  dgrdProducts.DataBind()
End Sub
</Script>

<html>
<head><title>CacheProducts.aspx</title></head>
<body>

<form Runat="Server">
<asp:DataGrid
  ID="dgrdProducts"
  AllowSorting="True"
  OnSortCommand="dgrdProducts_SortCommand"
  Runat="Server" />
</form>
</body>
</html>

_____________________________
Mehdi.
software engineering student.
Looking for a good job for summer 2005.