Hi,

I have a dropdown, which will select a table from the list and the Webdatagrid will display the values of that table in the grid. However, if I change the table from the dropdown again, it throws error as "DataKeyField is invalid". But I can see the valid DataKeyFields for the new table that I have selected. Please help me in this?

My aspx code:

protected void Page_Load(object sender, EventArgs e)
        {
            string table = DropDownList1.SelectedValue;

            if (table != "")
            {   
                SqlDataSource1.SelectCommand = "select * from [" + DropDownList1.SelectedValue + "]";
                WebDataGrid1.Visible = true;
                
                string connectionstring = ConfigurationManager.ConnectionStrings["TestConnectionString"].ConnectionString;

                using (SqlConnection conn = new SqlConnection(connectionstring))
                {
                    conn.Open();
                    string sql = "";

                    #region *** Get the primary keys ***

                    ArrayList alKeys = new ArrayList();

                    sql = String.Format("select c.COLUMN_NAME from INFORMATION_SCHEMA.TABLE_CONSTRAINTS pk, INFORMATION_SCHEMA.KEY_COLUMN_USAGE c where CONSTRAINT_TYPE = 'PRIMARY KEY' and c.TABLE_NAME = pk.TABLE_NAME and c.CONSTRAINT_NAME = pk.CONSTRAINT_NAME and pk.TABLE_NAME = '{0}'", table);
                    SqlCommand cmd = new SqlCommand(sql, conn);
                    cmd.CommandType = CommandType.Text;

                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        string keys = "";

                        while (reader.Read())
                        {
                            alKeys.Add(reader.GetString(0));
                            keys += reader.GetString(0) + ", ";
                        }

                        keys = keys.Substring(0, keys.Length - 2);

                        //set the grid's primary keys
                        WebDataGrid1.DataKeyFields = keys;
                    }

                    #endregion
                }
            }
            else
            {
                SqlDataSource1.SelectCommand = "SELECT 1";
                WebDataGrid1.Visible = false;
            }
        }

        protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
        {
           
            RefreshGrid();
        }

        private void RefreshGrid()
        {
           
            WebDataGrid1.DataBind();

            WebDataGrid1.ScrollLeft = 0;
            WebDataGrid1.ScrollTop = 0;

        }

Stack Trace:

[InvalidOperationException: DataKeyField is invalid] Infragistics.Web.UI.Framework.Data.DataSourceAdapter.Select(DataSourceSelectArguments arguments) +635 Infragistics.Web.UI.Framework.Data.DataSourceObjectView.ExecuteSelect(DataSourceSelectArguments arguments) +73 System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +19 System.Web.UI.WebControls.DataBoundControl.PerformSelect() +142 System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +73 Infragistics.Web.UI.GridControls.WebDataGrid.DataBind() +909 MyWeb.Default1.RefreshGrid() in E:\Project\ASP.NET\Practice\MyWeb\MyWeb\Default1.aspx.cs:229 MyWeb.Default1.DropDownList1_SelectedIndexChanged(Object sender, EventArgs e) in E:\Project\ASP.NET\Practice\MyWeb\MyWeb\Default1.aspx.cs:299 System.Web.UI.WebControls.ListControl.OnSelectedIndexChanged(EventArgs e) +111 System.Web.UI.WebControls.DropDownList.RaisePostDataChangedEvent() +134 System.Web.UI.WebControls.DropDownList.System.Web.UI.IPostBackDataHandler.RaisePostDataChangedEvent() +10 System.Web.UI.Page.RaiseChangedEvents() +165 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1485