在EF Core中查询继承表可以通过使用Table Per Hierarchy (TPH) 或 Table Per Type (TPT) 策略来实现。 1. Table Per Hierarchy ...
题外话: 继承不顺风水, 尽量少用, 我的从前的经验是 OData 配 Entity Framework 6.0 继承经常会出 Bug. 就不知道这么多年后的 EF Core 有没有改善. 参考 Docs – Inheritance How to configure inheritance mappings in Entity Framework 7 TPH (Table-per-hierarchy) 映射不只有一种方式, 目前一共有 3 种....
TPH(Table Per Hierarchy):所有的数据都放在同一个表内,但是使用辨别标志(Discriminator)的方式来区分,即通过Discriminator与DiscriminatorID来进行区分。 TPC(Table Per Concrete-Type):由具体类型的表来存放各自的数据,而各自没有任何关联,继承的实体会包含基类中的所有属性。 TPT(Table Per Type):表示每个对象各自独...
Table per Hierarchy (TPH) An entire class hierarchy can be mapped to a single table. This table includes columns forall propertiesofall classesin the hierarchy. The concrete subclass represented by a particular row is identified by the value of atype discriminator column. You don’t have to do...
TPH(Table Per Hierarchy) TPH:基类和派生类都映射到同一张表中,通过使用鉴别列来识别是否为子类型。这是Code First默认规则使用的表映射方法。 public class Lodging { public int LodgingId { get; set; } [Required] [MaxLength(200)] [MinLength(10)] ...
If you don't rely onconventions, you can specify the base type explicitly usingHasBaseType. You can also use.HasBaseType((Type)null)to remove an entity type from the hierarchy. Table-per-hierarchy and discriminator configuration By default, EF maps the inheritance using thetable-per-hierarchy...
EF Core の既定では、.NET 型の継承階層が 1 つのデータベース テーブルにマップされます。 これは、Table-Per-Hierarchy (TPH) マッピング戦略と呼ばれます。 EF Core 5.0 では、.NET 型ごとに異なるデータベース テーブルへのマッピングをサポートする、Table-Per-Type (TPT) 戦略が...
FeatureEF6.4EF Core Basic class mappingYes1.0 Constructors with parameters2.1 Property value conversions2.1 Mapped types with no keys2.1 ConventionsYes1.0 Custom conventionsYes7.0 Data annotationsYes1.0 Fluent APIYes1.0 Inheritance: Table per hierarchy (TPH)Yes1.0 ...
Previously, usingExcludeFromMigrationson a table in a TPC hierarchy would also exclude other tables in the hierarchy. New behavior Starting with EF Core 8.0,ExcludeFromMigrationsdoes not impact other tables. Why The old behavior was a bug and prevented migrations from being used to manage hierarch...
After Insert is done to first table, we need Id-s that were generated in Db because they are FK(ForeignKey) in second table. It is implemented with OUTPUT as part of MERGE Query, so in this case even the Insert is not done directly to TargetTable but to TempTable and then Merged with...