2.9.1. Natural Id Mapping

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Natural ids are defined in terms of one or more persistent attributes.

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<div class="title">Example 172. Natural id using single basic attribute</div>
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<pre class="prettyprint highlight">`@Entity
public class Company {

    @Id
    private Integer id;

    @NaturalId
    private String taxIdentifier;

    ...
}`</pre>
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<div class="title">Example 173. Natural id using single embedded attribute</div>
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<pre class="prettyprint highlight">`@Entity
public class PostalCarrier {

    @Id
    private Integer id;

    @NaturalId
    @Embedded
    private PostalCode postalCode;

    ...

}

@Embeddable
public class PostalCode {
    ...
}`</pre>
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<div class="title">Example 174. Natural id using multiple persistent attributes</div>
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<pre class="prettyprint highlight">`@Entity
public class Course {

    @Id
    private Integer id;

    @NaturalId
    @ManyToOne
    private Department department;

    @NaturalId
    private String code;

    ...
}`</pre>
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