how to fill data in comboBox. but error was found?

Question

try

{

string connString = @"Data Source=VINODKUMAR;Initial Catalog=ShreeSankalp;Persist Security Info=True;User ID=sa;Password=1234567890";

using (SqlConnection sqlConn = new SqlConnection(connString))

{

string sqlQuery = @"SELECT Batch No * from New Batchs";

SqlCommand cmd = new SqlCommand(sqlQuery, sqlConn);

SqlDataAdapter da = new SqlDataAdapter(cmd);

DataTable dt = new DataTable();

da.Fill(dt);

//dt.Columns.Add("Batch No", typeof (string));

comboBox1.DisplayMember = "Batch No";

comboBox1.DataSource = dt;

}

}

catch (Exception ex)

{

MessageBox.Show(ex.ToString());

MessageBox.Show("Please Enter Admission ID");

}