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Mapping the table and columns

To specify the mapping of the entity to a database table, we use @Table and @Column annotations (Example | 2-2).

Example 12-2 Entity with mapping to a database table

@Entity

@Table (schema="ITSO", name="CUSTOMER")

public class Customer implements java.io.Serializable {

	@Id

	@Column (name="SSN")

	private String ssn;

	@Column (name="LAST_NAME")

	private String lastName;

	private String title;

	private String firstNname;

	......

The @Table annotation provides information related to which table and schema the entity corresponds to.

The @Column annotation provides information related to which column is mapped by an entity property. By default, properties are mapped to columns with the same name, and the @Column annotation is used when the property and column names differ.

Note: Entities support two types of persistence mechanisms: Field-based persistence-The entity properties must be declared as public or protected and instruct the JPA provider to ignore getter/setters. Property-based persistence-You must provide getter/setter methods. We recommend to use the property-based approach (as in Example | 2-2), because it is more adherent to the Java programming guidelines.

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