EF Core GetAll 条目不包含所有条目的引用对象

Question

我在使用 EF 时遇到问题，当我获取包含关联活动列表的所有条目时。 那么只有最后一个条目引用了特定的活动，该活动在其活动列表中。

例如

1. Entry1

   有一个列表，其中包括

   Activity1

2. Entry2

   有一个列表，其中包括

   Activity1

3. 当我使用 EF 从数据库检索所有条目时。那么就只有

   Entry2

   包含

   Acivity1

   ，而不是两者都包含

我有以下 EF 配置

public class WeeklyReviewBlazorClientDbContext : WeeklyReviewDbContext
{
    public WeeklyReviewBlazorClientDbContext(DbContextOptions options) : base(options)
    {
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.ApplyConfigurationsFromAssembly(typeof(WeeklyReviewBlazorClientDbContext).Assembly);
    }
}

// Program.cs
builder.Services.AddDbContext<WeeklyReviewBlazorClientDbContext>(options =>
{
    //options.UseLazyLoadingProxies();
    options.UseInMemoryDatabase(databaseName: "WeeklyReview"); 
});

问题出在以下方法

public IEnumerable<EntryModel> GetAll()
{
    return _db.Entry.Include(x => x.Activities).Where(x => x.UserGuid == UserGuid).ToList();
    return _db.Entry.Include(x => x.Activities).Where(x => x.UserGuid == UserGuid).AsNoTracking().ToList(); // Also tried this
}

它没有返回我期望的结果。 下面的测试用例说明了我的意思。

public void Test()
{
    var aBreakfast = new Activity("Breakfast");
    var aDinner = new Activity("Dinner");
    AddEntry(aBreakfast);
    var entries1 = GetAll();    // Retrives one entry with a Breakfast Activity
    AddEntry(aDinner);          
    var entries2 = GetAll();    // Retrives two entries first with a Breakfast and second with a Dinner Activity
    AddEntry(aBreakfast);
    var entries3 = GetAll();    // Retrives three entries first without the Breakfast, second with Dinner and the last with the Breakfast Activity
                                // This should have returned a Breakfast, Dinner and a Breakfast
}

public void AddEntry(ActivityModel activity)
{
    var entry = new EntryModel(_timeService.Current, new List<ActivityModel>(), UserGuid);
    _db.Entry.Add(entry);
    entry.Activities = new List<ActivityModel>() { activity };
}

这两个型号是：

public class ActivityModel
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string NormalizedName { get; set; }
    public bool Deleted { get; set; }
    public CategoryModel Category { get; set; }
    public Guid UserGuid { get; set; }
}

public class EntryModel
{
    public int Id { get; set; }
    public DateTime StartTime { get; set; }
    public DateTime? EndTime { get; set; }
    public DateTime RecordedTime{ get; set; }
    public TimeSpan Duration => EndTime.HasValue ? EndTime.Value - StartTime : TimeSpan.Zero;
    public List<ActivityModel> Activities { get; set; } // Also tried 
    public bool Deleted { get; set; }
    public Guid UserGuid { get; set; }
}

我认为这与重复键有关，因为早餐活动由两个条目引用，因此最后一个条目是唯一能够引用它的条目。 因为第一个条目引用了早餐活动。

为了更好地了解上下文，您可以查看这里。

Answer 1

在您的 AddEntry 方法中，您应该将活动 add 到已存在的活动列表中。所以你的代码应该是：

public void AddEntry(ActivityModel activity)
{
    //I don't think this line of your code works, because there would be a constructor:
    var entry = new EntryModel(_timeService.Current, new List<ActivityModel>(), UserGuid);

    entry.Activities.Add(activity);
    _db.Entry.Add(entry);
}