samples/snippets/csharp/VS_Snippets_ADO.NET/DataWorks SampleApp.OleDb/CS/source.cs - main - aprogrammer/dotnet-docs

samples/snippets/csharp/VS_Snippets_ADO.NET/DataWorks SampleApp.OleDb/CS/source.cs

57 строк2 KB

Genevieve Warren

ropc fixes for ado.net (#42498)

07 сен 2024, 02:05

07 сен 2024, 02:05cdcd7c4


// <Snippet1>
using System;
using System.Data.OleDb;
using System.Runtime.Versioning;

// API is only supported on Windows
[SupportedOSPlatform("windows")]
static class Program
{
    static void Main()
    {
        const string connectionString =
        "Provider=Microsoft.Jet.OLEDB.4.0;Data Source="
            + "c:\\Data\\Northwind.mdb;...";

        // Provide the query string with a parameter placeholder.
        const string queryString =
            "SELECT ProductID, UnitPrice, ProductName from products "
                + "WHERE UnitPrice > ? "
                + "ORDER BY UnitPrice DESC;";

        // Specify the parameter value.
        const int paramValue = 5;

        // Create and open the connection in a using block. This
        // ensures that all resources will be closed and disposed
        // when the code exits.
        using (OleDbConnection connection =
            new(connectionString))
        {
            // Create the Command and Parameter objects.
            OleDbCommand command = new(queryString, connection);
            command.Parameters.AddWithValue("@pricePoint", paramValue);

            // Open the connection in a try/catch block.
            // Create and execute the DataReader, writing the result
            // set to the console window.
            try
            {
                connection.Open();
                OleDbDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    Console.WriteLine("\t{0}\t{1}\t{2}",
                        reader[0], reader[1], reader[2]);
                }
                reader.Close();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            Console.ReadLine();
        }
    }
    // </Snippet1>
}