hi, you can get id like below

<asp:ButtonField HeaderText="Material" CommandName="Material" Text="Select" />
    <asp:ButtonField HeaderText="Material1" CommandName="Material1" Text="Select" />
 
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
        {
               int index = ((e.CommandSource as Button).NamingContainer as GridViewRow).RowIndex;                int Id = Convert.ToInt32(GridOracle.DataKeys[index].Value);                 switch (e.CommandName)
                {
                        case "Material":
                                Response.Write("Material");
                                break;
                        case "Material1":
                                Response.Write("Material1");
                                break;
                }
        }

if you statisfied with my ans. mark both the replies as answered one.