Specifying entity inheritance

An entity may inherit properties from other entities. You can specify a specific strategy to use for inheritance.

Use this procedure to specify inheritance (@Inheritance) for an existing entity (@Entity):

  1. Select the entity in the Package Explorer.

  2. In the JPA Details view, select the Inheritance information.

    Specifying Inheritance

    Selecting the Inheritance area on the JPA Details view.
  3. In the Strategy list, select one of the following the inheritance strategies:

    • A single table (default)

    • Joined table

    • One table per class

  4. Use the following table to complete the remaining fields on the tab. See "Inheritance information" for additional details.

    Property Description Default
    Discriminator Column Name of the discriminator column when using a Single or Joined inheritance strategy.

    This field corresponds to the @DiscriminatorColumn annotation.

    Discriminator Type Set the discriminator type to Char or Integer (instead of its default: String). The Discriminator Value must conform to this type. String
    Discriminator Value Specify the discriminator value used to differentiate an entity in this inheritance hierarchy. The value must conform to the specified Discriminator Type.

    This field corresponds to the @DiscriminatorValue annotation.

    Override Default Use this field to specify custom primary key join columns.

    This field corresponds to the @PrimaryKeyJoinClumn annotation.

Eclipse adds the following annotations the entity field:

    referencedColumnName = "<REFERENCED_COLUMN_NAME>")

The following figures illustrates the different inheritance strategies.

Single Table Inheritance

This figure illustrates entity inheritance in a single table.

Joined Table Inheritance

This figure shows a sample joined inheritance table strategy.


Related reference


Related task

Adding persistence to a class


Related concept

Understanding Java persistence