>>> >>>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(); >>> } >>> } >>> >>>} >>> >>>>>