C#

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();

private void button1_Click(object sender, EventArgs e)
        {
            string wCS = @"Data Source =\Storage Card\ModeDifféré\BaseGmaoLocale.sdf;";
            SqlCeConnection sqlceconn = new SqlCeConnection(wCS);
            SqlCeCommand command = sqlceconn.CreateCommand();
            command.CommandText = "SELECT [ID]+\" \"+[Magasin]+\" \"+ [qtyonhand] AS IMQ from stocks where ID like %@txt%";
            SqlCeDataAdapter adapter = new SqlCeDataAdapter(command);
            SqlCeParameter txt = new SqlCeParameter("@txt", SqlDbType.NVarChar);
            txt.Value= textBox1.Text;
            command.Parameters.Add(txt);
            DataSet ds = new DataSet();
            adapter.Fill(ds);
            listBox1.DataSource = ds.Tables[0];
            listBox1.DisplayMember="IMQ";
        }

there is an error parsing the querry. [token line number =1, token line offset=77, Token in error = %]