更新繼承實體，實體框架7

Question

我有以下BaseballDbContext類：

public class BaseballDbContext : DbContext 
{ 
    public DbSet<BaseballTeam> teams { get; set; } 

    protected override void OnModelCreating(ModelBuilder modelBuilder) 
    { 
     modelBuilder.Entity<Hitter>(); 
     modelBuilder.Entity<Pitcher>(); 
    } 
} 

我的模型類是：在球員表

public class BaseballTeam 
{ 
    public int Id { get; set; } 
    public string teamName { get; set; } 
    public List<BaseballPlayer> players { get; set; } 
} 

public abstract class BaseballPlayer 
{ 
    public int Id { get; set; } 
    public int age { get; set; } 
    public string name { get; set; } 
} 

public class Hitter : BaseballPlayer 
{ 
    public int homeruns { get; set; } 
} 

public class Pitcher : BaseballPlayer 
{ 
    public int strikeouts { get; set; } 
} 

開始播種數據：

現在我想更新name和擊球手之一的homeruns性質：

BaseballTeam team = _ctx.teams.Include(q => q.players).FirstOrDefault(); 
Hitter hitter = team.players.OfType<Hitter>().FirstOrDefault(); 
hitter.name = "Tulowitzki"; //that property will be updated 
hitter.homeruns = 399;  //but that will not :(

int i = team.players.FindIndex(q => q.Id == hitter.Id); 
team.players[i] = hitter; 

_ctx.Update(team); 
_ctx.SaveChanges(); 

後，我運行的代碼只有玩家的名字得到了更新，但不是本壘打屬性：兩個孩子的

如何更新屬性和父類？

Answer 1

從這個答案，但是這是一個解決方法：Save changes to child class properties using base class query with Entity Framework TPH patten：

不跟蹤使用AsNoTracking（）的變化

using (var context = new BaseballDbContext()) 
{ 
    var team = context.teams.Include(q => q.players).AsNoTracking().FirstOrDefault(); 
    var hitter = team.players.OfType<Hitter>().FirstOrDefault(); 
    hitter.name = "Donaldson"; 
    hitter.homeruns = 999; 
    context.Update(team); 
    context.SaveChanges(); 
} 

我想你應該有一個看看opened issues related to inheritance和可能開個新的問題