To use Npgsql to query a scaffolded database and send the values to Azure Service Bus in C# using Visual Studio Code (VSC), you can follow the steps below:

1. Create a console application in Visual Studio Code using C#.

2. Install the required packages:

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- Install Npgsql: `dotnet add package Npgsql`
- Install Azure.Messaging.ServiceBus: `dotnet add package Azure.Messaging.ServiceBus`

1. Next, add the following code at the top of your C# file to enable you to use Npgsql and Azure.ServiceBus packages:

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using Npgsql;
using Azure.Messaging.ServiceBus;

1. Set up a connection string to connect to the PostgreSQL database you want to query. You can provide the connection string as a command-line argument at runtime or store it in a configuration file. Here is an example connection string:

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Server=<server>;Port=<port>;User Id=<username>;Password=<password>;Database=<database>;Integrated Security=true;Pooling=true;

1. Use the Npgsql package to connect to the PostgreSQL database and execute a SELECT statement to retrieve the data you want. Here is an example code to establish connection to the database and retrieve data:

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static async Task<List<string>> QueryDatabase()
{
    var connectionString = Environment.GetEnvironmentVariable("DB_CONNECTION_STRING");

    await using var conn = new NpgsqlConnection(connectionString);
    await conn.OpenAsync();

    using var cmd = new NpgsqlCommand("SELECT col1,col2,col3 FROM table", conn);

    var results = new List<string>();
    await using (var reader = await cmd.ExecuteReaderAsync())
    {
        while (await reader.ReadAsync())
        {
            var row = (string)reader["col1"] + ";" + (string)reader["col2"] + ";" + (string)reader["col3"];
            results.Add(row);
        }
    }

    return results;
}

This function will return a list of strings with results where each string contains the values of all columns included in the SELECT statement separated by a semi-colon.

1. Finally, use the Azure.Messaging.ServiceBus package to create and send messages to the Azure Service Bus queue or topic. Here is an example code to create a client for the Service Bus and send messages:

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static async Task SendMessage(IList<string> messages)
{
    var connectionString = Environment.GetEnvironmentVariable("SERVICE_BUS_CONNECTION_STRING");

    await using var client = new ServiceBusClient(connectionString);
    var sender = client.CreateSender("<queue-or-topic-name>");

    foreach (var message in messages)
    {
        await sender.SendMessageAsync(new ServiceBusMessage(message));
        Console.WriteLine($"Message sent: {message}");
    }

    await client.DisposeAsync();
}

Note that you'll need to replace <queue-or-topic-name> with the name of the queue or the topic you want to send the messages to.

That's it! Once you have implemented these methods, you can call them at runtime to get data from PostgreSQL and send it to the Azure Service Bus queue or topic.