Gridview - select

open the second page with post parameters of the foreign key from the selected record

I'm not so sure how to do that. Could you help?

Your data grid should have an ItemCommand event that fires when you click the button.  The event handler will have an argument (the variable is "e") from which you will be able to get info about the ID.  You should have the CustomerID as a non-visible field in your grid (maybe make it the very first column).  In the ItemCommand event, do this:

// this assumes the customer id is the first column, but can be made not visible.
string custID = e.Item.Cells[0].Text;

// redirect the browser to the other page.
string url = String.Concat("OtherPage.aspx?CustID=", custID);
Response.Redirect(url);

This will cause the other page to show with the customer id in the querystring (the part of the url after the question mark).

Then in OtherPage.aspx, you can code the Page_Load event to get this value like this:

// get the id...
int custID = Convert.ToInt32(Request.QueryString["CustID"]);

Then use this to query your database for that customer's info and show on the page.

John

I'm using VB. The equavalent of ItemCommand in GridView is RowCommand. However, I don't see "item" here.
   
Protected Sub GridView1_RowCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles GridView1.RowCommand

        Dim custID As String = e.item.Cells(0).Text             ----------------------------------------error item
        Dim url As String = [String].Concat("OtherPage.aspx?CustID=", custID)
        Response.Redirect(url)

    End Sub

OtherPage.aspx

I get this error - Input string was not in a correct format.


Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load


        Dim custID As Integer = Convert.ToInt32(Request.QueryString("CustID"))   ------->>>>Input string was not in a correct format.

        If Not IsPostBack Then
            Try

                Dim Constr As String = " mystring"
                Dim con As New SqlConnection(Constr)
                Dim Comstr As String = "select *from residence where id = CustID"
                Dim da As New SqlDataAdapter(Comstr, con)
                Dim ds As New DataSet

                da.Fill(ds, "table1")



                Me.GridView1.DataSource = ds
                Me.GridView1.DataMember = "table1"
                Me.GridView1.DataBind()



            Catch ex As Exception

                Response.Write(ex.ToString)


            End Try


        End If


    End Sub

What is customerID? Text?

It is number.

System.InvalidCastException: Conversion from string "" to type 'Integer' is not valid. ---> System.FormatException: Input string was not in a correct format. at Microsoft.VisualBasic.CompilerServices.Conversions.ParseDouble(String Value, NumberFormatInfo NumberFormat) at Microsoft.VisualBasic.

No, it's an empty string. Conversion from string "" to Integer is not valid. The value is not being passed to that page.

I set a property "DatakeyNames"  to CustomerID         ------this is on  Gridview1

How can I correct it then?

The code that I helped you with takes the text  value of the Cell(0) of the grid and passes it through. What is this value?

It is empty  -  ""

If that is the correct value that you are trying to pass through, and it's empty, look into why.
Is the data correct?
Is this a null value coming back from the database?
Should you be trying to pass a different cell (e.g. cell(1) or cell(2))?
Is there another property that you should be passing (e.g. DatakeyNames)?

I changed this
Dim ID As String = row.Cells(0).Text

to

Dim ID As String = row.Cells(1).Text

On Otherpage.aspx - I get the same table from my first page
It does display the record the selected on the address bar  - http://localhost/Sample/OtherPage.aspx?ID=6

Why I won't display just the record I select on Gridview?

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load


        Dim custID As Integer = Convert.ToInt32(Request.QueryString("CustID"))  
        If Not IsPostBack Then
            Try

                Dim Constr As String = " mystring"
                Dim con As New SqlConnection(Constr)
                Dim Comstr As String = "select *from residence where id = CustID"
                Dim da As New SqlDataAdapter(Comstr, con)
                Dim ds As New DataSet

                da.Fill(ds, "table1")



                Me.GridView1.DataSource = ds
                Me.GridView1.DataMember = "table1"
                Me.GridView1.DataBind()



            Catch ex As Exception

                Response.Write(ex.ToString)


            End Try


        End If


    End Sub

correction   - Dim Comstr As String = "select *from residence where id = ID"

I corrected this line -   Dim Comstr As String = "select *from residence where id = ID"

to

  Dim Comstr As String = "select *from residence where id =" & ID

I finally works...wow

Goodnight, Nightman - Thank you so much for the help

Hehe, good morning you mean (9.30 am here in sunny South Africa).

Cheers
Night

Don't forget to PAQ this question. Also, don't forget to delete the pointer question (https://www.experts-exchange.com/questions/22033181/Need-help-with-this-question.html) - I deliberately didn't post anything there so that you can delete it quickly and get the 50 points refunded.