Hibernate @Embeddable and @Embedded Annotation (original) (raw)

Last Updated : 23 Apr, 2026

@Embeddable and @Embedded are JPA annotations used to model reusable value objects within an entity. They allow grouping related fields into a separate class and storing them in the same table as the parent entity without creating a new table.

• No separate table is created for the embedded class
• Both annotations are used together for proper mapping
• Helps organize complex data into reusable components

@Embeddable

@Embeddable is used to define a class whose fields can be embedded into another entity. This class does not exist independently in the database and is always used as part of another entity.

• Does not have its own identity or primary key
• Cannot be persisted independently
• Provides a reusable structure for grouping fields Java `

@Embeddable public class Address { private String street; private String city; private String state; private String zip; // getters and setters }

`

@Embedded

@Embedded is used inside an entity to include an @Embeddable class as a field. It ensures that all fields of the embedded object are stored in the same table as the parent entity.

• Used only within entity classes
• Maps embedded fields to the parent table
• Supports column customization using overrides Java `

@Entity public class Employee { @Id private int id; private String name; @Embedded private Address address; // getters and setters }

`

**Explanation:

• The Address class is marked with @Embeddable, so it can be used inside another class as a value object. The Employee class uses @Embedded to include Address, which allows all its fields to be stored in the same table as Employee.
• When an Employee is saved, the Address fields are stored in the same table with a prefix like address_.

Note: You can also use the @AttributeOverrides to customize the column name mapping.

Java `

@Embedded @AttributeOverrides({ @AttributeOverride(name = "street", column = @column(name = "home_street")) }) private Address address;

`

**Explanation: The above example will map the street property of the Address class to home_street in the database table.

Advantages of @Embeddable and @Embedded annotations

• **Code Reusability: We can reuse the embeddable class in multiple entities, avoiding duplication of code.
• **Normalization: It can reduce the number of tables by embedding related fields into a single table, improving simplicity and read performance, though this approach is closer to denormalization than normalization.
• **Data Integrity: It ensures data integrity by maintaining the relationship between the embeddable and the containing class.
• **Simplicity: It simplifies the development process by reducing the number of classes and tables required to map the data.
• **Better Data Modelling: It allows for better data modeling by allowing you to encapsulate the properties of an object within another object, making the data structure more intuitive and easy to understand.

@Embeddable vs @Embedded