GridView Linking column values

Question

I have two gridviews in seperate screens.

GridView1

 ID    Product    Date           Amount
 1       Car1     02/03/2014    $ 15,000
 1       Car2     05/03/2014    $ 10,000 
 2       Bike     01/01/2014    $  2,500
 3       Bus      06/04/2014    $ 25,000

GridView2

 ID    Product    Date           Amount
 1       Car2     05/03/2014    $ 25,000 
 2       Bike     01/01/2014    $  2,500
 3       Bus      06/04/2014    $ 25,000

Gridview2 sums up similar ID row values from GridView1 and displays in GridView2 picking the latest effective Date.

Now I am showing my ID column in GridView2 as LinkButton. When I click on value 1 in GridView2 ID column it has to navigate to GridView1 and show only values of ID 1 in the grid.

Code Behind:

GridView1

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            GridView1.DataSource = DataRepository.GetG1();
            GridView1.DataBind();
        }
    }

public static DataTable GetG1()
    {
        DataTable dt = new DataTable();
        string strcon = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        using (SqlConnection conn = new SqlConnection(strcon))
        {
            conn.Open();
            string strQuery = "Select * from ManLog";
            SqlCommand cmd = new SqlCommand(strQuery, conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(dt);
        }
        return dt;
    }

GridView2

protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            GridView2.DataSource = DataRepository.GetG2();
            GridView2.DataBind();
        }
    }

public static DataTable GetG2()
    {
        DataTable dt = new DataTable();
        string strcon = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        using (SqlConnection conn = new SqlConnection(strcon))
        {
            conn.Open();
            string strQuery = "Select ID, Product, max(Date),sum(Amount) from ManLog";
            SqlCommand cmd = new SqlCommand(strQuery, conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(dt);
        }
        return dt;
    }

Link Button for GridView 2:

<asp:TemplateField HeaderText="ID" SortExpression="ID">
    <HeaderStyle HorizontalAlign="Center"></HeaderStyle>
    <ItemStyle HorizontalAlign="Center" Width="25%" />
    <EditItemTemplate>
    <asp:TextBox ID="txtID" Width="100%" runat="server" Enabled="false" Text='<%# Eval("ID") %>'></asp:TextBox>
    </EditItemTemplate>
    <ItemTemplate>
        <asp:LinkButton ID="lblID" runat="server" Text='<%# Eval("ID") %>' />
    </ItemTemplate>
</asp:TemplateField>

Answer 1

I'm not sure what exactly your question is or how your page is laid out, but I think you need to set the url in the GridView2 link to something like GridView1Page.aspx?id=1 then use that QueryString to only load the given id. If you don't use the url or don't want to post, then try a Session variable.

So in your grid binding method you have something like:

if (Request.QueryString["id"] != null)
{
    //load some: select * from table where id = Request.QueryString["id"] 
}
else
{
    //load all (select * from table)
}

Answer 2

Update your GetG1 method to the following one:

public static DataTable GetG1(int? id=null)
{
    DataTable dt = new DataTable();
    string strcon = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
    using (SqlConnection conn = new SqlConnection(strcon))
    {
        conn.Open();

        if(id.HasValue)
        {
            string strQuery = "Select * From ManLog Where Id=@id";
            SqlCommand cmd = new SqlCommand(strQuery, conn);
            cmd.Parameter.Add(new SqlParameter("id",id.Value);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(dt);
        }
        else
        {
            string strQuery = "Select * From ManLog";
            SqlCommand cmd = new SqlCommand(strQuery, conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(dt);
        }
    }

    return dt;
}

Then as already Joel posted, you should pass an id to the link of your second gridview. For this reason you should update the Page_Load event handler of your first web form, where GridView1 resides.

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        int id;
        if(int.TryParse(Request.QueryString["id"], out id)
        {

            GridView1.DataSource = DataRepository.GetG1(id);
            GridView1.DataBind();
        }
        else
        {
            GridView1.DataSource = DataRepository.GetG1();
            GridView1.DataBind();
        }
    }
}

Last but not least you should update the corresponding links in GridView2.

<ItemTemplate> 
    <asp:LinkButton ID="lblEAICode" runat="server" Text='<%# Eval("EAI_Code") %>' />
</ItemTemplate>

At the Text attribute you should place '../../gridview1.aspx?id=<%# Eval("EAI_Code") %>', where ../../gridview1.aspx is the relative path of the web form in which gridview1 resides.

UPDATE

<asp:LinkButton runat="server" CommandArgument='<%# Eval("EAI_Code") %>' OnCommand="LinkButton_Click" Text="View"> </asp:LinkButton> 

add the following handler for the click event of your link button in your code behind class

protected void LinkButton_Click(Object sender, CommandEventArgs e)
{
    if (e.CommandArgument != null)
    {
        Response.Redirect("../Product%20Profit.aspx?id=" + e.CommandArgument.ToString());
    }
}