如何在Code First Entity Framework中避免使用“ discriminator”列 [英] How can 'discriminator' column be avoidable in Code First Entity Framework

问题描述

如果我从模型类继承我的业务类（模型类映射在数据库表上），那么如何避免在数据库内部创建一个列作为 Discriminator。

<因为目前，如果我将我的业务类（例如，Specifics）继承到现有的模型类（例如，DataSpecific），它会要求代码优先迁移。在迁移中，我可以将鉴别器视为新列。我真的不想要这个因为在整个应用程序中都使用了原始模型类，所以该代码可以正常工作。

如何停止创建描述符列

C＃代码：

模型类

 公共类DataSpecific 
 {
 
} 
  

商务舱

 公共舱特定
 {
 
} 
  

结果，我可以在迁移中看到以下代码

  AddColumn（ dbo.Consignments， Discriminator，c => c.String（nullable：false，maxLength：128））; 
  

如何避免这种情况？

解决方案

要么应用 NotMapped 对您的业务类别的数据注释：

  [NotMapped] 
 public class Specific：数据特定
 {
} 
  

或使用 忽略 Fluent API：

  modelBuilder.Ignore< Specific>（）; 
  

How can I avoid creating a column as "Discriminator" inside the database , If I inherit my business class from model class ( model class is mapped on database table).

Because, at the moment, if I inherit my business class ( e.g Specifics) to an existing model class ( i.e DataSpecific ), It asks for code first migration. In the migration, I can see discriminator as new column. I really don't want this. Because, original model class is being used in the whole application and that code works fine.

How can I stop the creation of "descriminator" column

C# Code :

Model Class

public class DataSpecific
{

}

Busines Class

public class Specific
{

}

as a result I can see following code in the migration

 AddColumn("dbo.Consignments", "Discriminator", c => c.String(nullable: false, maxLength: 128));

How can I avoid this?

解决方案

Either apply NotMapped Data Annotation to your business class:

[NotMapped]
public class Specific : DataSpecific
{
}

or use Ignore Fluent API:

modelBuilder.Ignore<Specific>();

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