Visual Studio + SQLPlus Integration.

Integration code:
```cs
using System;
using System.Data.SqlClient;

class Program
{
    static void Main(string[] args)
    {
        string connectionString = "Data Source=(local);Initial Catalog=Northwind;Integrated Security=True";
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();
            Console.WriteLine("Connection opened successfully.");
        }
    }
}
```