Parent Value Error When Trying To Use A 'where' In My Query.

I'm building a page that will display link categories with the links under each one.  I have that part working however there is a code issue that I cant quite figure out related to the SQL query.

I want to be able to have the category only display if the 'linkcolumn' is set to 1 in the database. (so I can later separate which ones show in each column of the page.

However, I get an error if I try to make my 'select' statement have a 'where' in it. I think it does this because it ends up not showing all the records but I'm not sure why.

Exception Details: System.ArgumentException: This constraint cannot be enabled as not all values have corresponding parent values.

My codebehind file:

using System;

using System.Data;

using System.Configuration;

using System.Collections;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Data.SqlClient;

using System.Data.Sql;using System.Data.SqlTypes;

public partial class Modules_NCG_NCGLinks : System.Web.UI.UserControl

{public void Page_Load(object sender, EventArgs e)

{

//Create the connection and DataAdapter for the Category table.SqlConnection cnn = new SqlConnection(ConfigurationManager.ConnectionStrings["mystringname"].ConnectionString);

SqlDataAdapter cmd1 = new SqlDataAdapter("select * from NCG_Links_Category Where LinkCategory = 'Test'",cnn);

//Create and fill the DataSet.DataSet ds = new DataSet();

cmd1.Fill(ds, "NCG_Links_Category");

//Create a second DataAdapter for the Links table.SqlDataAdapter cmd2 = new SqlDataAdapter("select * from NCG_Links",cnn);

cmd2.Fill(ds,"NCG_Links");

//Create the relation bewtween the Category and Links tables.ds.Relations.Add("myrelation",

ds.Tables["NCG_Links_Category"].Columns["LinkCategory"],ds.Tables["NCG_Links"].Columns["LinkCategory"]);

//Bind the Category table to the parent Repeater control, and call DataBind.parentRepeater.DataSource = ds.Tables["NCG_Links_Category"];

Page.DataBind();

//Close the connection.

cnn.Close();

}private void Page_Init(object sender, EventArgs e)

{

InitializeComponent();

}private void InitializeComponent()

{ this.Load += new System.EventHandler(this.Page_Load);

}

}