Hibernate Join two unrelated table when both has Composite Primary Key

Question

I\'m writing java application using hibernate 5.2 but without HQL

there is two table, Transactions and ResponseCode

Answer 1

Your mapping of both entities is wrong.

Let's start with the ResponseCode entity. Your table model shows a composite primary key that consists of the RcCode and Lang columns. But your entity mapping only declares the rcCode attribute as the primary key. You need to add an additional @Id annotation to the rcLang attribute of the ResponseCode entity.

This should be the fixed mapping of the ResponseCode entity:

@Entity
@Table(name = "response_codes")
public class ResponseCode implements java.io.Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @Column(name = "response_code")
    private String rcCode;

    @Column(name = "rc_status")
    private String rcStatus;

    @Column(name = "rc_description")
    private String rcDesc;

    @Id
    @Column(name = "rc_lang")
    private String rcLang;

    // Contructors and getters/setters
}

After fixing the primary key of your ReponseCode entity, you need to reference both attributes/columns in the association mapping of your Transaction entity. With Hibernate 5.2, you can do that with 2 of Hibernate's @JoinColumn annotations. Older Hibernate versions and the JPA standard in version 2.1 need to wrap these annotations in an additional @JoinColumns annotation.

Here is the fixed mapping of your Transaction entity:

@Entity
@Table(name = "transactions")
public class Transaction implements java.io.Serializable {
    private static final long serialVersionUID = 1L;

    @Column(name = "merchant_id", nullable = true)
    private String merchantID;

    @Column(name = "tran_amount", nullable = true)
    private String tranAmount;

    @Id
    @Column(name = "tran_type", nullable = true)
    private String tranType;

    @Column(name = "auth_request_date", nullable = true)
    @Temporal(TemporalType.TIMESTAMP)
    private Date authRequestDate;

    @Id
    @Column(name = "tran_id", nullable = true)
    private String tranID;

    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name="rc_id", referencedColumnName = "id")
    @JoinColumn(name="rc_lang", referencedColumnName = "lang")
    private ResponseCode rc;

    // Contructos and getters/setters