看看这个msdn教程：使用DataReader检索数据

样本：

        SqlDataReader rdr = null;
        SqlConnection con = null;
        SqlCommand cmd = null;

        try
        {
            // Open connection to the database
            string ConnectionString = "server=xeon;uid=sa;"+
                "pwd=manager; database=northwind";
            con = new SqlConnection(ConnectionString);
            con.Open();

            // Set up a command with the given query and associate
            // this with the current connection.
            string CommandText = "SELECT FirstName, LastName" +
                                 "  FROM Employees" +
                                 " WHERE (LastName LIKE @Find)";
            cmd = new SqlCommand(CommandText);
            cmd.Connection = con;

            // Add LastName to the above defined paramter @Find
            cmd.Parameters.Add(
                new SqlParameter(
                "@Find", // The name of the parameter to map
                System.Data.SqlDbType.NVarChar, // SqlDbType values
                20, // The width of the parameter
                "LastName"));  // The name of the source column

            // Fill the parameter with the value retrieved
            // from the text field
            cmd.Parameters["@Find"].Value = txtFind.Text;

            // Execute the query
            rdr = cmd.ExecuteReader();

            // Fill the list box with the values retrieved
            lbFound.Items.Clear();
            while(rdr.Read())
            {
                lbFound.Items.Add(rdr["FirstName"].ToString() +
                " " + rdr["LastName"].ToString());
            }
        }
        catch(Exception ex)
        {
            // Print error message
            MessageBox.Show(ex.Message);
        }
        finally
        {
            // Close data reader object and database connection
            if (rdr != null)
                rdr.Close();

            if (con.State == ConnectionState.Open)
                con.Close();
        }