using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;

namespace enitty_test
{
    class Program
    {
        public class Planet
        {
            [Key]
            public string Name { get; set; }
            public decimal AverageDistanceFromSun { get; set; }
        }

        public class PlanetContext : DbContext
        {
            public PlanetContext()
            {
                Database.EnsureCreated();
            }

            public DbSet<Planet> Planets { get; set; }

            protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
                 => optionsBuilder.UseNpgsql("Host=localhost;Database=entity;Username=postgres;Password=qwerty");
        }

        static void Main(string[] args)
        {
            using (var context = new PlanetContext())
            {

                var jupiter = new Planet
                {
                    Name = "Jupiter",
                    AverageDistanceFromSun = 775
                };
                context.Planets.Update(jupiter);
                context.SaveChanges();
            }

            using (var context = new PlanetContext())
            {
                var jupiter = context.Planets.Single(p => p.Name == "Jupiter");
                Console.WriteLine($"Jupiter is {jupiter.AverageDistanceFromSun} million km from the sun.");
            }
        }
    }
}