JPA Annotations - How to retrieve a single value from a different table than the current object?

annotations, hibernate, hibernate-annotations, java, jpa

Solution

Use a secondary table. This allows you to map for an entity, on a one-to-one basis, another table and define column mappings that use it.

Example:

@Entity
@Table(name = "foo")
@SecondaryTable(name = "other_table", pkJoinColumns=@PrimaryKeyJoinColumn(name="id", referencedColumnName="FOO_ID"))
public class Foo {
    @Id
    @Column(name="FOO_ID")
    private String fooId;

    @Column(name="FOO_A")
    private String fooA;

    @Column(table="OtherTable", name="barCode")
    private String barCode;
}

Problem

How do you map a single value from a column in another table to the current object? Example: ``` class Foo { @Id @Column(name="FOO_ID") private String fooId; @Column(name="FOO_A") private String fooA; //Column to map to another table? //is a one to one mapping - but don't want a separate object for this. private String barCode; } ``` Table: `Fields` Foo: `FOO_ID, FOO_A` Bar: `FOO_ID, BAR_CODE` How do I retrieve the `BAR_CODE` field without creating a separate object (or a secondary table) using `JPA annotations`?

Original source

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