Thank you for your answer.

But how would I do that?
Because if it is null, is it your intention to replace it with "" in case of
a strng and a 0 in case of a integer?

Then I should put the following code in the code behind like:

...
for each (Column cl in ds.Tables[i].Rows[j].Columns) )
{
 if (cl.IsDBnull(cl))
 {
   if (cl.Type == DataType.Integer)
   {
      cl.Value = 0;
   }
   ....
}
ds.ApplyUpdates()

something like this?

Or is there another way?

Thank you for your response.
I don't know how to create a strong typed dataset, I will show you how I get
my data.
I'm using the folling DataHandler to get my data:

using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace meetmate.DataLayer
{
    /// <summary>
    /// Summary description for DataHandler.
    /// </summary>
    public class DataHandler
    {
        private SqlConnection conn;
        private string connectionString;

        public DataHandler()
        {
            connectionString = ConfigurationSettings.AppSettings["connectionString"];
            conn = new SqlConnection(connectionString);               
        }

        public DataSet GetDataSet(SqlCommand cmd)
        {
            cmd.Connection = conn;
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);

            return ds;
        }

        public void ExecuteCommand(SqlCommand cmd)
        {
            cmd.Connection = conn;
            try
            {
                conn.Open();
                cmd.ExecuteNonQuery();
            }
            finally
            {
                conn.Close();
            }
        }
    }
}

In another module I call the Get like this:

public DataSet GetMeetingByID(int meetingID)
        {
            string qry = "select
titel,datum,tijd_van,tijd_tot,adres,plaats,tekst,verslag " +
                        "from Meetings " +
                        "where ID = @ID";
            SqlCommand cmd = new SqlCommand(qry);
            cmd.Parameters.Add(new SqlParameter("@ID",meetingID));
            DataHandler dh = new DataHandler();
            DataSet ds = dh.GetDataSet(cmd);
               
            return ds;
        }

Then, in my BusinessLayer, I call the GetMeetingByID.
Do you know or have a reference how I could use typed DataSet in this?

Thank you,
Eddy

Thanks for your response!