Database

internal ObservableCollection<INVCategory> GetCategoryList()
{
      DataLoadOptions dataLoadOptions = new DataLoadOptions();
      dataLoadOptions.LoadWith<INVCategory>(t => t.INVSubCategories);
      this.Context.LoadOptions = dataLoadOptions;
             
      var categories = from category in this.Context.INVCategories
                       orderby category.CatgeoryId descending
                       select category;
      return new   ObservableCollection<INVCategory>(categories.ToList());
}

<ComboBox Grid.Column="1" Grid.Row="0" HorizontalAlignment="Stretch"  VerticalAlignment="Stretch" Margin="0,2,10,2" TabIndex="0" x:Name="categoryComboBox" ItemsSource="{Binding CategoryList}" IsEditable="True" DisplayMemberPath="CategoryName"  SelectedValuePath="CatgeoryId" SelectedItem="{Binding CategoryList, Mode=TwoWay}" SelectedValue="{Binding Path=CurrentEntity.CategoryId, Mode=TwoWay}">
</ComboBox>

<ComboBox Grid.Column="1" Grid.Row="1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="0,2,10,2" TabIndex="1" ItemsSource="{Binding SelectedItem, ElementName=categoryComboBox, Mode=OneWay}" DisplayMemberPath="SubCategoryName" SelectedValuePath="SubCategoryId" SelectedItem="{Binding INVSubCategories, Mode=TwoWay}" >
</ComboBox>

SELECT tbl_band_songs.id3_artist, tbl_band_songs.Artist, tbl_band_songs.id, tbl_band_songs.id3_title

FROM tbl_band_songs, tbl_song_lyrics

WHERE tbl_band_songs.id3_artist = 239 AND tbl_band_songs.id <> tbl_song_lyrics.Sng_ID

Date             ID

 2009-07-01            1
 2009-07-01            2
 2009-07-01            3
 2009-08-01            4
 2009-08-01            5
 2009-08-01            6
 2009-09-01            7
 2009-09-01            8
 2009-10-01            9
 2009-10-01            10
 2009-11-01            11

Date               Start            End
2009-07              1               3
2009-08              4               6
2009-09              7               8

string sConnection = "Provider=SQLNCLI.1;Persist Security Info=False;User ID=sa;Initial Catalog=GMAO;Data Source=127.0.0.1,1433;Password=sa;";
            string sSQL = "SELECT com FROM energie; ";
            SqlConnection conn = new SqlConnection(sConnection);
            SqlCommand comm = new SqlCommand(sSQL, conn);
            DataSet ds = new DataSet();

            SqlDataAdapter da = new SqlDataAdapter(sSQL,conn);   
            SqlDataReader dr = null;
            try
            {
                comm.Connection.Open();
                da.Fill(ds, "SQL Temp Table");
                foreach (DataRow d in ds.Tables[0].Rows)
                {
                    MessageBox.Show("xxxx");
                    comboBox1.Items.Add(d.ItemArray[0].ToString());
                }  

            }
            catch (SqlException ex)
            {
                MessageBox.Show("connexion impossible");
                MessageBox.Show(ex.Message);
                return;
            }

            dr.Close();
            comm.Connection.Close();