具有继承的 EF Core Fluent API 配置

Question

EF CORE Fluent API 单独文件中的配置在简单类 Ref #1 && Ref # 2 中工作正常。当实体继承自KeyedEntity或AuditableEntity时，问题就来了

class abstract KeyedEntity<TValue> {
public TValue Id {get; set;}
}
class abstract  AuditableEntity<TValue> : KeyedEntityBase<TValue>{
public DateTime DateCreated {get; set;}
public DateTime DateModified {get; set;}
}

映射器是这样的

public class KeyedEntityMap<TEntity, TId>
: IEntityTypeConfiguration<TEntity> where TEntity
: KeyedEntityBase<TId> where TId : struct
{
public void Configure(EntityTypeBuilder<TEntity> builder)
{
// Primary Key
builder.HasKey(t => t.Id);
// Properties
builder.Property(t => t.Id).HasColumnName("id").ValueGeneratedOnAdd();
}
}
public class AuditableEntityMap<TEntity, TId>
: IEntityTypeConfiguration<TEntity>    where TEntity 
: AuditableEntity<TId>    where TId : struct
{
public void Configure(EntityTypeBuilder<TEntity> builder)
{
// Properties
builder.Property(t => t.DateCreated).HasColumnName("DateCreated");
builder.Property(t => t.DateModified).HasColumnName("DateModified");           
}
}

现在，从AuditableEntity继承的实体出现问题。我需要从该特定 Enitity 类注册 Map 以及AuditableEntityMap类和KeyedEntityMap类。

现在我可以忘记地图继承并将所有复杂的继承地图合并到实体类中，我不想这样做并尊重 DRY .复杂继承的问题是它没有注册我的实体映射

Answer 1

有几种方法可以为基本实体配置实现 DRY。

最接近当前设计的位是简单地遵循配置类中的实体层次结构：

public class KeyedEntityMap<TEntity, TId> : IEntityTypeConfiguration<TEntity>
where TEntity : KeyedEntityBase<TId>
where TId : struct
{
public virtual void Configure(EntityTypeBuilder<TEntity> builder)
//       ^^^
{
// Primary Key
builder.HasKey(t => t.Id);
// Properties
builder.Property(t => t.Id).HasColumnName("id").ValueGeneratedOnAdd();
}
}
public class AuditableEntityMap<TEntity, TId> : KeyedEntityMap<TEntity, TId>
//                                                 ^^^
where TEntity : AuditableEntity<TId>
where TId : struct
{
public override void Configure(EntityTypeBuilder<TEntity> builder)
//       ^^^
{
base.Configure(builder); // <<<
// Properties
builder.Property(t => t.DateCreated).HasColumnName("DateCreated");
builder.Property(t => t.DateModified).HasColumnName("DateModified");           
}
}

然后对于需要额外配置的特定实体：

public class Person : AuditableEntity<int>    
{
public string Name { get; set; }
}

您将注册

public class PersonEntityMap : AuditableEntityMap<Person, int>
{
public override void Configure(EntityTypeBuilder<Person> builder)
{
base.Configure(builder);
// Properties
builder.Property(t => t.Name).IsRequired();
// etc...
}
}