EF CoreのOwned typesのサンプル

Character.sql

use Test;

begin tran;

-- テーブル作成
drop table if exists dbo.Character;
create table dbo.Character(
	Id int,
	Name nvarchar(4) not null,
	Level int not null,
	Hp int not null,
	Mp int not null,
	constraint PK_Character primary key(Id)
);

/*
-- データ投入
insert into dbo.Character(
	Id, Name, Level, Hp, Mp
)
output inserted.*
values
	(1, N'エイト', 10, 59, 32),
	(2, N'ゼシカ', 10, 47, 28);
*/

commit;

Program.cs

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;

namespace ConsoleApp {
	// ステータス
	public class Status {
		// HP
		public int Hp { get; set; }
		// MP
		public int Mp { get; set; }
	}
	/*
	public class Status {
		// 最大HP
		public int MaxHp { get; set; }
		// 最大MP
		public int MaxMp { get; set; }
		// ちから
		public int Strength { get; set; }
		// すばやさ
		public int Speed { get; set; }
		// みのまもり
		public int Guard { get; set; }
		// かしこさ
		public int Wisdom { get; set; }
		// 攻撃力
		public int Attack { get; set; }
		// 守備力
		public int Defense { get; set; }
	}
	*/

	// キャラクター
	public class Character {
		public int Id { get; set; }
		public string Name { get; set; }
		public int Level { get; set; }
		public Status Status { get; set; }
	}

	// ロガープロバイダー
	public class AppLoggerProvider : ILoggerProvider {
		public ILogger CreateLogger(string categoryName) {
			if (string.Equals(categoryName, DbLoggerCategory.Database.Command.Name)) {
				return new ConsoleLogger();
			}

			return NullLogger.Instance;
		}

		public void Dispose() {
		}

		// ロガー
		private class ConsoleLogger : ILogger {
			public IDisposable BeginScope<TState>(TState state) => null;

			// 情報レベル以上のログを有効にする
			public bool IsEnabled(LogLevel logLevel) => logLevel >= LogLevel.Information;

			public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception,
				Func<TState, Exception, string> formatter) {
				Console.WriteLine(formatter(state, exception));
				Console.WriteLine("---");
			}
		}
	}

	// DBコンテキスト
	public class AppDbContext : DbContext {
		public AppDbContext(bool tracking = false) {
			ChangeTracker.QueryTrackingBehavior = tracking
				? QueryTrackingBehavior.TrackAll
				: QueryTrackingBehavior.NoTracking;
		}

		protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
			var connectionString = new SqlConnectionStringBuilder {
				DataSource = ".",
				InitialCatalog = "Test",
				IntegratedSecurity = true,
			}.ToString();

			optionsBuilder.UseSqlServer(connectionString);
		}

		protected override void OnModelCreating(ModelBuilder modelBuilder) {
			// Characterテーブルへのマッピング
			modelBuilder.Entity<Character>().ToTable(nameof(Character));

			// CharacterがStatusを所有する
			modelBuilder.Entity<Character>().OwnsOne(
				character => character.Status,
				statusBuilder => {
					// Statusをカラムへマッピング
					// デフォルトだと「Status_Hp」「「Status_Mp」」といったカラムにマッピングされる
					statusBuilder.Property(status => status.Hp).HasColumnName(nameof(Status.Hp));
					statusBuilder.Property(status => status.Mp).HasColumnName(nameof(Status.Mp));
				});
		}
	}

	class Program {
		private static void Dump(IEnumerable<Character> characters) {
			foreach (var character in characters) {
				Console.WriteLine($"{character.Name}");
				Console.WriteLine($"Lv {character.Level}");
				Console.WriteLine($"HP {character.Status.Hp}");
				Console.WriteLine($"MP {character.Status.Mp}");
				Console.WriteLine();
			}
		}

		static void Main(string[] args) {
			using (var dbContext = new AppDbContext()) {
				// ロガープロバイダーを設定
				var serviceProvider = dbContext.GetInfrastructure();
				var loggerFactory = serviceProvider.GetService<ILoggerFactory>();
				loggerFactory.AddProvider(new AppLoggerProvider());
			}

			// データ投入
			using (var dbContext = new AppDbContext(tracking: true)) {
				dbContext.Set<Character>().AddRange(
					new Character {
						Id = 1,
						Name = "エイト",
						Level = 10,
						Status = new Status { Hp = 59, Mp = 32 },
					},
					new Character {
						Id = 2,
						Name = "ゼシカ",
						Level = 10,
						Status = new Status { Hp = 47, Mp = 28 },
					});

				dbContext.SaveChanges();
				/*
				Executed DbCommand(36ms) [Parameters=[@p0='?', @p1='?', @p2='?' (Size = 4000), @p3='?', @p4='?', @p5='?', @p6='?', @p7='?' (Size = 4000), @p8='?', @p9='?'], CommandType='Text', CommandTimeout='30']
				SET NOCOUNT ON;
				INSERT INTO[Character] ([Id], [Level], [Name], [Hp], [Mp])
				VALUES(@p0, @p1, @p2, @p3, @p4),
				(@p5, @p6, @p7, @p8, @p9);
				---
				*/
			}

			// 確認
			using (var dbContext = new AppDbContext()) {
				var characters = dbContext.Set<Character>().ToList();
				/*
				Executed DbCommand (1ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
				SELECT [c].[Id], [c].[Level], [c].[Name], [c].[Id], [c].[Hp], [c].[Mp]
				FROM [Character] AS [c]
				---
				*/
				Dump(characters);
				/*
				エイト
				Lv 10
				HP 59
				MP 32

				ゼシカ
				Lv 10
				HP 47
				MP 28
				*/
			}

			// データ更新
			using (var dbContext = new AppDbContext(tracking: true)) {
				// エイトを取得
				var character = dbContext.Set<Character>().Find(1);
				/*
				Executed DbCommand(1ms) [Parameters=[@__get_Item_0='?'], CommandType='Text', CommandTimeout='30']
				SELECT TOP(1) [e].[Id], [e].[Level], [e].[Name], [e].[Id], [e].[Hp], [e].[Mp]
						FROM[Character] AS[e]
				WHERE[e].[Id] = @__get_Item_0
				---
				*/

				// エイトがレベルアップ
				character.Level += 1;
				character.Status.Hp += 12;
				character.Status.Mp += 2;

				dbContext.SaveChanges();
				/*
				SET NOCOUNT ON;
				UPDATE [Character] SET [Level] = @p0, [Hp] = @p1, [Mp] = @p2
				WHERE [Id] = @p3;
				SELECT @@ROWCOUNT;
				---
				*/
			}

			// 確認
			using (var dbContext = new AppDbContext()) {
				var characters = dbContext.Set<Character>().ToList();
				/*
				Executed DbCommand(0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
				SELECT[c].[Id], [c].[Level], [c].[Name], [c].[Id], [c].[Hp], [c].[Mp]
				FROM[Character] AS[c]
				---
				*/

				Dump(characters);
				/*
				エイト
				Lv 11
				HP 71
				MP 34

				ゼシカ
				Lv 10
				HP 47
				MP 28
				*/
			}
		}
	}
}