Using Inherited Entity Class in asp.net EF Core - entity-framework

Question

I have following Entity Class (Which mapped directly to table of SQL Server DB)
public class PROCESSCARD : BaseClass
{
[Key]
[Display(Name = "Card No")]
public String ProcessCardID { get; set; }
[Display(Name = "Entry Date")]
public DateTime EntryDate { get; set; }
[Display(Name ="Job Type")]
public String JobType { get; set; }
[Display(Name = "Job / Non Job")]
public String JobNonJob { get; set; }
[Display (Name = "Cost Booking")]
public String CostBooking { get; set; }
[Display(Name = "Planned Hrs/Qty")]
public Decimal? PlannedHours { get; set; }
}
Above class inherits from BaseClass which is as follow
public class BaseClass
{
[NotMapped]
public String StatusMessage { get; set; }
}
Now upto this there is no issue everything is just fine,
but I am storing deleted data of entity PROCESSCARD to PROCESSCARD_HIST, and I want to show deleted history data to user.
Structures of both entity (PROCESSCARD and PROCESSCARD_HIST are ditto same) so I created another entity class PROCESSCARD_HIST, and to avoid duplicate members, I inherited PROCESSCARD_HIST from PROCESSCARD,
public class PROCESS_CARD_HIST : PROCESS_CARD
{
}
but now when I try to access data from PROCESSCARD_HIST class, it throws error like "Invalid column name 'Discriminator'",
Any Idea how I can achieve this?

Answer 1

If you don't want to repeat the properties in both classes, introduce another unmapped superclass
public class ProcessCardBase : BaseClass
{
[Key]
[Display(Name = "Card No")]
public String ProcessCardID { get; set; }
[Display(Name = "Entry Date")]
public DateTime EntryDate { get; set; }
[Display(Name ="Job Type")]
public String JobType { get; set; }
[Display(Name = "Job / Non Job")]
public String JobNonJob { get; set; }
[Display (Name = "Cost Booking")]
public String CostBooking { get; set; }
[Display(Name = "Planned Hrs/Qty")]
public Decimal? PlannedHours { get; set; }
}
Then
public class ProcessCard : ProcessCardBase
{
}
public class ProcessCardHistory : ProcessCardBase
{
}