源代码The following example shows what a simple ADO.NET application that connects to the Northwind database and returns a list of Categories would look like. The example writes the output to the console, or command prompt.



The following example shows what a simple ADO.NET application that connects to the Northwind database and returns a list of Categories. The example writes the output to the console, or command prompt.



SqlClient

[Visual Basic]

Imports System

Imports System.Data

Imports System.Data.SqlClient

Imports Microsoft.VisualBasic



Public Class Sample



  Public Shared Sub Main()

    Dim nwindConn As SqlConnection = New SqlConnection("Data Source=localhost;" & _

                                                       "User Id=sa;Password=pwd;Initial Catalog=northwind")



    Dim catCMD As SqlCommand = nwindConn.CreateCommand()

    catCMD.CommandText = "SELECT CategoryID, CategoryName FROM Categories"



    nwindConn.Open()



    Dim myReader As SqlDataReader = catCMD.ExecuteReader()



    Do While myReader.Read()

      Console.WriteLine(vbTab & "{0}" & vbTab & "{1}", myReader.GetInt32(0), myReader.GetString(1))

    Loop



    myReader.Close()

    nwindConn.Close()

  End Sub

End Class

[C#]

using System;

using System.Data;

using System.Data.SqlClient;



class Sample

{

  public static void Main()

  {

    SqlConnection nwindConn = new SqlConnection("Data Source=localhost;User Id=sa;Password=pwd;Initial Catalog=northwind");



    SqlCommand catCMD = nwindConn.CreateCommand();

    catCMD.CommandText = "SELECT CategoryID, CategoryName FROM Categories";



    nwindConn.Open();



    SqlDataReader myReader = catCMD.ExecuteReader();



    while (myReader.Read())

    {

      Console.WriteLine("\t{0}\t{1}", myReader.GetInt32(0), myReader.GetString(1));

    }



    myReader.Close();

    nwindConn.Close();

  }

}

OleDb

[Visual Basic]

Imports System

Imports System.Data

Imports System.Data.OleDb

Imports Microsoft.VisualBasic



Public Class Sample



  Public Shared Sub Main()

    Dim nwindConn As OleDbConnection = New OleDbConnection("Provider=SQLOLEDB;Data Source=localhost;" & _

                                                           "User Id=sa;Password=pwd;Initial Catalog=northwind")



    Dim catCMD As OleDbCommand = nwindConn.CreateCommand()

    catCMD.CommandText = "SELECT CategoryID, CategoryName FROM Categories"



    nwindConn.Open()



    Dim myReader As OleDbDataReader = catCMD.ExecuteReader()



    Do While myReader.Read()

      Console.WriteLine(vbTab & "{0}" & vbTab & "{1}", myReader.GetInt32(0), myReader.GetString(1))

    Loop



    myReader.Close()

    nwindConn.Close()

  End Sub

End Class

[C#]

using System;

using System.Data;

using System.Data.OleDb;



class Sample

{

  public static void Main()

  {

    OleDbConnection nwindConn = new OleDbConnection("Provider=SQLOLEDB;Data Source=localhost;User Id=sa;Password=pwd;Initial Catalog=northwind");



    OleDbCommand catCMD = nwindConn.CreateCommand();

    catCMD.CommandText = "SELECT CategoryID, CategoryName FROM Categories";



    nwindConn.Open();



    OleDbDataReader myReader = catCMD.ExecuteReader();



    while (myReader.Read())

    {

      Console.WriteLine("\t{0}\t{1}", myReader.GetInt32(0), myReader.GetString(1));

    }



    myReader.Close();

    nwindConn.Close();

  }

}