Question

允许这个人问别人帮助这个人。

这是将我的数据库应用程序从SQLalchemy迁移到EF Core。

因为EF Core支持每种类型的表（联合表继承）。

我在下面显示我的代码

班级

public class Degreaser_Old
{
    public Degreaser_Old()
    { }

    public Degreaser_Old(string tubname)
    {
        ChemistryContext Context = ContextMaker.MainContext();
        DegreaserPosNavigation = Context.DegreaserPos
                                        .Include(s => s.Degreaser)
                                        .SingleOrDefault(s => s.EngName == tubname);
    }

    public int DegreaserCode { get; set; }
    public int SarogateKey { get; set; }
    public int DegreaserPos { get; set; }
    public double DegreaserConc { get; set; }
    public string Type { get; set; }
    public DegreaserPos DegreaserPosNavigation { get; set; }
    public virtual MeasureDay SarogateKeyNavigation { get; set; }
}

public class Degreaser : Degreaser_Old
{
    public Degreaser()
    { }

    public Degreaser(string tubname) : base(tubname)
    { }

    public decimal Level { get; protected set; }
    public decimal Volume { get; protected set; }
}

上下文配置（流利的API）

modelBuilder.Entity<Degreaser_Old>(entity =>
        {
            entity.ToTable("Degreaser");
            entity.HasKey(e => e.DegreaserCode);

            entity.HasAlternateKey(a => new { a.SarogateKey, a.DegreaserPos });

            entity.HasIndex(e => new { e.SarogateKey, e.DegreaserPos })
                                        .IsUnique(true);
            entity.HasDiscriminator(c => c.Type)
                .HasValue<Degreaser_Old>("Old")
                .HasValue<Degreaser>("Degreaser");
            entity.HasIndex(e => e.SarogateKey)
                .HasDatabaseName("Degreaser$測定日コード");
            entity.Property(e => e.DegreaserCode).ValueGeneratedOnAdd();
            entity.Property(e => e.DegreaserConc).HasPrecision(5, 2);
            entity.Property(e => e.DegreaserPos).HasColumnName("Degreaser_Pos");
            entity.Property(e => e.DegreaserCode).ValueGeneratedOnAdd();
            entity.Property(e => e.Type);
            entity.HasOne(d => d.DegreaserPosNavigation)
                .WithMany(p => p.Degreaser)
                .HasForeignKey(d => d.DegreaserPos)
                .OnDelete(DeleteBehavior.ClientSetNull)
                .HasConstraintName("Degreaser${8BC67109-2594-4BBD-848F-EB4D77039677}");

            entity.HasOne(d => d.SarogateKeyNavigation)
                .WithMany(p => p.Degreasers)
                .HasForeignKey(d => d.SarogateKey)
                .OnDelete(DeleteBehavior.ClientSetNull)
                .HasConstraintName("Degreaser${5C8E5635-10BD-4124-8D13-FCC511573DC5}");
        });
        modelBuilder.Entity<Degreaser>(entity =>
        {
            entity.ToTable("Degreaser_Vol");
            entity.HasBaseType<Degreaser_Old>();
            entity.Property(c => c.Level).HasMaxLength(5);
            entity.Property(c => c.Volume).HasPrecision(4,2);
        });

运行添加迁移时的消息

“ Degreaser”映射到表“ Degreaser_Vol”，而“ Degreaser_Old”映射到表“ Degreaser”。将层次结构中的所有实体类型映射到同一张表或删除区分符，并将它们全部映射到不同的表。有关更多信息，请参见https://go.microsoft.com/fwlink/?linkid=2130430。

这个可以理解的说法是必须使用TPH或TPC。

但是这个人没有足够的知识来解决它。

这个问题困扰着我。

EF Core 5：使用TPT进行迁移

0 个答案: