# Mapped superclass

An entities that extend a Mapped Superclass class inherit the persistent state and mapping information from a superclass. You should use a mapped superclass to define mapping information that is common to multiple entity classes.

A mapped superclass can be:

- Abstract or concrete classes

A mapped superclass cannot be:

- Be queried or passed as an argument to Entity-Manager or Query operations

- Be the target of a persistent relationship

A mapped superclass does not have a defined database table. Instead, its mapping information is derived from its superclass. To override the mapping information for a specific subclass, use the `@AttributeOverride` annotation for that specific class.

A mapped superclass is identified by the `@MappedSuperclass` annotation.

Use this procedure to add Mapped Superclass persistence to an existing entity:

1. Right-click the class in the Package Explorer and select Persistence > Make Java Persistence Entity.

   Adding Persistence to a Class

2. In the Persistence Properties view, use the Map As drop-list to select Mapped Superclass.

   Selecting Mapped Superclass Persistence

3. Complete the remaining Persistence Properties view (for entities).

Adding persistence to a class