>Forget that hungarian crap that Michel uses.... program to the interface...
>
>
>
>

>
>using System;
>using System.Data;
>using System.Data.Common;
>using System.Data.OleDb;
>using System.Data.SqlClient;
>using Microsoft.Data.Odbc;
>
>namespace GenericDataAccessApp
>{
>    public class GenericAdoNetComp
>    {
>        private IDbConnection idbConn = null;
>        private IDbDataAdapter idbAdapter = null;
>        private DbDataAdapter dbAdapter = null;
>        private IDataReader iReader = null;
>
>        public GenericAdoNetComp()
>        {
>        }
>
>        // GetConnection returns IDbConnection
>        public IDbConnection GetConnection(int connType,
>        string connString)
>        {
>            switch (connType)
>            {
>                case 1: // OleDb Data Provider
>                    idbConn = new OleDbConnection(connString);
>                    break;
>                case 2: // Sql Data Provider
>                    idbConn = new SqlConnection(connString);
>                    break;
>                case 3: // ODBC Data Provider
>                    idbConn = new OdbcConnection(connString);
>                    break;
>                // case 3: // Add your custom data provider
>                default:
>                    break;
>            }
>            return idbConn;
>        }
>
>        // GetDataAdapter returns IDbDataAdapter
>        public IDbDataAdapter GetDataAdapter(int connType,
>        string connString, string sql)
>        {
>            switch (connType)
>            {
>                case 1: // OleDb Data Provider
>                    idbAdapter = new OleDbDataAdapter(sql, connString);
>                    break;
>                case 2: // Sql Data Provider
>                    idbAdapter = new SqlDataAdapter(sql, connString);
>                    break;
>                case 3: // ODBC Data Provider
>                    idbAdapter = new OdbcDataAdapter(sql, connString);
>                    break;
>                // case 3: // Add your custom data provider
>                default:
>                    break;
>            }
>            return idbAdapter;
>        }
>    }
>
>
>}
>
>
>
>public class Client
>{
>    private void ConnectBtn_Click(object sender, System.EventArgs e)
>    {
>        GenericAdoNetComp genDP = new GenericAdoNetComp();
>        sql = "SELECT * FROM Employees";
>
>        if (radioButton1.Checked)
>        {
>            connString =
>            "Provider=Microsoft.Jet.OLEDB.4.0; Data
>Source=c:\\Northwind.mdb";
>            conn = genDP.GetConnection(1, connString);
>            adapter = genDP.GetDataAdapter(1, connString, sql);
>        }
>        else if (radioButton2.Checked)
>        {
>            connString =
>            "Data Source=MCB;Initial Catalog=Northwind;user
>id=sa;password=;";
>            conn = genDP.GetConnection(2, connString);
>            adapter = genDP.GetDataAdapter(2, connString, sql);
>        }
>        else if (radioButton3.Checked)
>        {
>            // Construct your connection string here
>            conn = genDP.GetConnection(3, connString);
>            adapter = genDP.GetDataAdapter(3, connString, sql);
>        }
>
>        try
>        {
>            conn.Open();
>            // Fill a DataSet
>            DataSet ds = new DataSet();
>            adapter.Fill(ds);
>            dataGrid1.DataSource = ds.Tables[0].DefaultView;
>        }
>        catch (Exception exp)
>        {
>            MessageBox.Show(exp.Message);
>        }
>        finally
>        {
>            conn.Close();
>        }
>    }
>
>}
>
>

Another question I have on the code above (sorry for addressing the question to you, John, but it is rather to anyone who could see what I am missing). On the client side, why the variables 'conn' and 'adapter' are not declared? In my tests this causes an error. But maybe I am missing something. I would appreciate your help.