Question

我正在使用EntityFrameworkCore。

我有一个带有鉴别器的参考数据表

CREATE TABLE ReferenceData(
  Id uniqueidentifier,
  Discriminator varchar(255),
  Value varchar(255),
  SecondaryValue varchar(255),
   CONSTRAINT [PK_dbo.ReferenceData] PRIMARY KEY CLUSTERED 
(
  [Id] ASC
)) ON [PRIMARY]

我的DbContext映射了这个

public class WeddingDbContext : DbContext
{
    public DbSet<WeddingEvent> WeddingEvents { get; set; }

    public DbSet<StarterChoice> StarterChoices { get; set; }

    public DbSet<MainChoice> MainChoices { get; set; }

    public DbSet<DessertChoice> DessertChoices { get; set; }

    public WeddingDbContext(DbContextOptions<WeddingDbContext> dbContextOptions)
        : base(dbContextOptions)
    {
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<ReferenceData>()
            .HasDiscriminator<string>("Discriminator")
            .HasValue<WeddingEvent>("WeddingEvent")
            .HasValue<StarterChoice>("StarterChoice")
            .HasValue<MainChoice>("MainChoice")
            .HasValue<DessertChoice>("DessertChoice");

        base.OnModelCreating(modelBuilder);
    }
}

当我使用它时，它可以完美地工作，就像我希望的那样。

using (WeddingDbContext context = new WeddingDbContext(contextOptions))
{
    foreach (WeddingEvent weddingEvent in context.WeddingEvents)
    {
        Console.WriteLine($"weddingevent: {weddingEvent.Value}");
    }
}

我的问题是当我向DbContext添加一个新类时，它开始期望在WeddingEvent模型中有一个新列，我无法弄清楚为什么会这样。

public class WeddingDbContext : DbContext
{
    // This is new
    public DbSet<Invite> Invites { get; set; }

    public DbSet<WeddingEvent> WeddingEvents { get; set; }

    // The rest of the DbSets shown above here
}

这是新的邀请类

public class Invite
{
    internal Invite(
        IEnumerable<WeddingEvent> weddingEvents)
    {
        WeddingEvents = weddingEvents.ToList();
    }

    protected Invite()
    {
    }

    public virtual ICollection<WeddingEvent> WeddingEvents { get; private set; }
}

SQL查询变为：

SELECT [r].[Id], [r].[Discriminator], [r].[Value], [r].[InviteId]
FROM [ReferenceData] AS [r]
WHERE [r].[Discriminator] = N'WeddingEvent'

为什么要尝试选择InviteId？有人可以帮忙吗？

添加DbSet会在EntityFrameworkCore中为现有模型添加意外的列

0 个答案: