.net编程

开发平台：

Visual C++

ConnectedApplication.cpp：源码内容

							// This is the main project file for VC++ application project 
// generated using an Application Wizard.
#include "stdafx.h"
#using <mscorlib.dll>
#using <System.dll>        // For Console I/O
#using <System.Data.dll>   // For ADO.NET
using namespace System;
using namespace System::Data;              // Generic ADO.NET definitions
using namespace System::Data::SqlClient;   // Specific definitions for SQL Server data provider
// This is the entry point for this application
#ifdef _UNICODE
int wmain(void)
#else
int main(void)
#endif
{
	// Create a SqlConnection object
	SqlConnection * cnPubs = new SqlConnection();
	
	// Set the connection string
	cnPubs->ConnectionString = S"data source=(local);integrated security=true;initial catalog=Pubs";
	
	try
	{
		// Try to open the connection
		cnPubs->Open();
	    Console::WriteLine(S"Connected to database successfully!");
		// Create a command object
		SqlCommand * cmTitles = new SqlCommand();
		cmTitles->CommandText = S"SELECT COUNT(*) FROM Titles";
		cmTitles->CommandType = CommandType::Text;
		cmTitles->Connection = cnPubs;
		// Execute a SQL statement that returns a scalar value, and display results
		Object * numberOfTitles = cmTitles->ExecuteScalar();
        Console::Write(S"Number of titles: ");
		Console::WriteLine(numberOfTitles);
		// Execute a SQL statement that modifies the database, and display results
		cmTitles->CommandText = S"UPDATE titles SET price = price * 1.05 WHERE price IS NOT NULL";
		int rowsAffected = cmTitles->ExecuteNonQuery();
        Console::Write(S"Number of titles increased in price: ");
		Console::WriteLine(rowsAffected);
		// Execute a SQL statement that queries the database
		cmTitles->CommandText = S"SELECT title, price FROM titles";
		// Execute the query
		SqlDataReader * reader = cmTitles->ExecuteReader();
		// Display the query results
		Console::WriteLine(S"n---------------------------------------------");
		while (reader->Read())
		{
			Console::Write(reader->GetString(0));
			Console::Write(S", ");
			if (reader->IsDBNull(1))
				Console::WriteLine(S"No price yet");
			else
				Console::WriteLine(reader->GetDecimal(1));
		}
		Console::WriteLine(S"---------------------------------------------");
		
		// Close the reader
		reader->Close();
	}
	catch (SqlException * Xcp)
	{
		Console::Write(S"Error occurred: ");
		Console::WriteLine(Xcp->Message);
	}
	// Close the connection
	if (cnPubs->State != ConnectionState::Closed)
	{
		cnPubs->Close();
	}
    Console::WriteLine(S"The database connection is now closed");
}

						