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这是父抽象类：

public enum RequestType
{
    TaxiRequester,
    WomenTaxiRequester,
    LuxaryTaxiRequester,
    MotrCycleRequester,
    VanetRequester
}
public enum PaymentType
{
    Cash = 0,
    Credit=1,
    Free=2
}

public abstract class Request
{
    protected Request()
    {
        PersonsRequests = new HashSet<PersonRequest>();
        WorkerRequestNotification= new HashSet<WorkerRequestNotification>();
    }

    #region EFValidator

    [Required]
    [Key]
    #endregion

    public Guid RequestId { get; set; }
    #region EFValidator

    [Required]

    #endregion

    public string CodeSafar { get; set; }

    #region EFValidator

    [Required]

    #endregion

    public DateTime RequestDate { get; set; }
    #region EFValidator

    [Required]

    #endregion

    public DateTime RequestWorkDate { get; set; }

    #region EFValidator

    [Column(TypeName = "nvarchar(max)")]

    #endregion

    public string DestinationAddress { get; set; }
    #region EFValidator

    [Column(TypeName = "nvarchar(max)")]
    [Required]
    #endregion

    public string DestinationLat { get; set; }
    #region EFValidator

    [Column(TypeName = "nvarchar(max)")]
    [Required]
    #endregion

    public string DestinationLon { get; set; }
    #region EFValidator

    [Required]

    #endregion
    public DateTime ApproveDate { get; set; }
    public DateTime DoneDate { get; set; }
    #region EFValidator

    [Required]

    #endregion

    public long Price { get; set; }
    #region EFValidator

    [Required]

    #endregion

    public Status Status { get; set; }
    #region EFValidator

    [Required]

    #endregion

    public PaymentType PaymentType { get; set; }

    #region EFRelation
    public virtual ICollection<PersonRequest> PersonsRequests { get; set; }
    public virtual ICollection<WorkerRequestNotification> WorkerRequestNotification { get; set; }
    public virtual ICollection<Chat> Chats { get; set; }

    #endregion

    #region RatingRelations

    public virtual Rating Rating { get; set; }

    #endregion

这是一个子抽象类：

public abstract class TransportRequest : Request
{
    #region EFValidator

    [Required]
    [Column(TypeName = "nvarchar(max)")]

    #endregion

    public string SourceAddress { get; set; }
    #region EFValidator

    [Required]
    [Column(TypeName = "nvarchar(max)")]

    #endregion

    public string SourceLat { get; set; }
    #region EFValidator

    [Required]
    [Column(TypeName = "nvarchar(max)")]

    #endregion

    public string SourceLon { get; set; }

    #region EFValidator

    [Required]

    #endregion

    public double Distance { get; set; }
    #region EFValidator

    [Column(TypeName = "nvarchar(max)")]

    #endregion

    public string DirectionPoints { get; set; }
}

这些是另一个儿童班：

public class RequestTaxi : TransportRequest
{

}
public class RequestVanet: TransportRequest
{

}
 public class RequestWomenTaxi : TransportRequest
{

}
 public class RequestMotorCycle: TransportRequest
{

}
public class RequestLuxaryTaxi: TransportRequest
{

}

这是我的 ApplicationDBContext 类相关代码：

model.Entity<Request>()
            .HasMany(p => p.Chats)
            .WithOne(b => b.Request)
            .HasForeignKey(p => p.RequestId);
        model.Entity<Request>()
            .HasMany(p => p.PersonsRequests)
            .WithOne(b => b.Request)
            .HasForeignKey(p => p.RequestId);
        model.Entity<Request>()
            .HasOne(p => p.Rating)
            .WithOne(b => b.Request)
            .HasForeignKey<Rating>(p => p.RequestId);
        model.Entity<Request>()
            .HasMany(p => p.WorkerRequestNotification)
            .WithOne(b => b.Request)
            .HasForeignKey(p => p.RequestId);

        model.Entity<Request>().Property(p => p.RequestId).ValueGeneratedOnAdd();
        model.Entity<Request>()
            .HasDiscriminator<int>(name: "Type")
            .HasValue<RequestTaxi>(value: Convert.ToInt32(value: RequestType.TaxiRequester))
            .HasValue<RequestWomenTaxi>(value: Convert.ToInt32(value: RequestType.WomenTaxiRequester))
            .HasValue<RequestLuxaryTaxi>(value: Convert.ToInt32(value: RequestType.LuxaryTaxiRequester))
            .HasValue<RequestMotorCycle>(value: Convert.ToInt32(value: RequestType.MotrCycleRequester))
            .HasValue<RequestVanet>(value: Convert.ToInt32(value: RequestType.VanetRequester));

这是我的迁移课程：

protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropIndex(
            name: "IX_Request_CodeSafar",
            table: "Request");

        migrationBuilder.AlterColumn<string>(
            name: "CodeSafar",
            table: "Request",
            nullable: false,
            oldClrType: typeof(string));

        migrationBuilder.AddColumn<string>(
            name: "RequestMotorCycle_DirectionPoints",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<double>(
            name: "RequestMotorCycle_Distance",
            table: "Request",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestMotorCycle_SourceAddress",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestMotorCycle_SourceLat",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestMotorCycle_SourceLon",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestTaxi_DirectionPoints",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<double>(
            name: "RequestTaxi_Distance",
            table: "Request",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestTaxi_SourceAddress",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestTaxi_SourceLat",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestTaxi_SourceLon",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestVanet_DirectionPoints",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<double>(
            name: "RequestVanet_Distance",
            table: "Request",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestVanet_SourceAddress",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestVanet_SourceLat",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestVanet_SourceLon",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestWomenTaxi_DirectionPoints",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<double>(
            name: "RequestWomenTaxi_Distance",
            table: "Request",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestWomenTaxi_SourceAddress",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestWomenTaxi_SourceLat",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "RequestWomenTaxi_SourceLon",
            table: "Request",
            type: "nvarchar(max)",
            nullable: true);

        migrationBuilder.CreateIndex(
            name: "IX_Person_ApplicationUsersId1",
            table: "Person",
            column: "ApplicationUsersId",
            unique: true);

        migrationBuilder.CreateIndex(
            name: "IX_Person_ApplicationUsersId2",
            table: "Person",
            column: "ApplicationUsersId",
            unique: true);

        migrationBuilder.CreateIndex(
            name: "IX_Person_ApplicationUsersId3",
            table: "Person",
            column: "ApplicationUsersId",
            unique: true);

        migrationBuilder.AddForeignKey(
            name: "FK_Person_ApplicationUsers_ApplicationUsersId1",
            table: "Person",
            column: "ApplicationUsersId",
            principalTable: "ApplicationUsers",
            principalColumn: "Id");

        migrationBuilder.AddForeignKey(
            name: "FK_Person_ApplicationUsers_ApplicationUsersId2",
            table: "Person",
            column: "ApplicationUsersId",
            principalTable: "ApplicationUsers",
            principalColumn: "Id");

        migrationBuilder.AddForeignKey(
            name: "FK_Person_ApplicationUsers_ApplicationUsersId3",
            table: "Person",
            column: "ApplicationUsersId",
            principalTable: "ApplicationUsers",
            principalColumn: "Id");
    }

我的问题是为什么要添加这样的列：

请求MotorCycle_DirectionPoints

并为每五个孩子上课重复？

事实上，我有六个 DirectionPoints 列！！！

例如，我怎样才能只有一个 DirectionPoints？

4

1 回答 1

4

问题是所有这些属性都在TransportRequest类中定义，但未TransportRequest指定为实体（仅是Request最终派生实体），因此 EF Core 假定它只是一个基类，并且所有派生类属性都不同。

EF Core 文档的包含和排除类型部分解释了哪些类被标识为实体：

DbSet按照惯例，在您的上下文的属性中公开的类型包含在您的模型中。此外，OnModelCreating方法中提到的类型也包括在内。最后，通过递归探索已发现类型的导航属性找到的任何类型也包含在模型中。

如您所见，TransportRequestis not a DbSet, 中未提及OnModelCreating且未由导航属性引用。

要解决此问题，只需在以下位置“提及”它OnModelCreating：

// ...
model.Entity<TransportRequest>();
// ...
于 2018-06-08T18:41:45.167 回答