CODEWITHSUNDEEP
hibernatejpaspring-data-jpa
chandrashekar.n
chandrashekar.n

Reputation: 374

One to mapping between to composite primary keys jpa

I do have a use case two tables are having composite primary key, one table have relation with another table in database , how to get that relationship in program level , how to declare the bean class

//Composite primary key of the table Project

    @Embeddable
    @Data
    public class ProjectId implements Serializable {

        private static final long serialVersionUID = 12233365L;

        @Column(name = "PROJECT_CODE")
        private Integer pCode;

        @Column(name = "BOL")
        private String bol;

        @Column(name = "BOLS")
        private String bols;

        @Column(name = "EID")
        private Integer eId;

    }

//Project class

public class Project implements Serializable {

    private static final long serialVersionUID = 748569L;

    @EmbeddedId
    private ProjectId projectId;

    @Column(name = "UPDATED_DATE")
    private Date updatedDate;

    @Column(name = "CREATED_DATE")
    private Date createdDate;

}

//pcode, bol, bols, eId are composite key

// Document table, Here some more interesting realtionshipp between Project,Document is "pcode, bol, bols, eId + did"

@Embeddable
@Data
public class DocumentId implements Serializable {

    private static final long serialVersionUID = 458933256L;

    @Column(name = "PROJECT_CODE")
    private Integer pCode;

    @Column(name = "BOL")
    private String bol;

    @Column(name = "BOLS")
    private String bols;

    @Column(name = "EID")
    private Integer eId;

    @Column(name = "DID")
    private String dId;
}

//Document table

@Entity
@Table(name = "DOCUMENT")
@Data
public class Documents implements Serializable {

    private static final long serialVersionUID = 14578523695L;

    @EmbeddedId
    private DocumentId documentId;

    @Column(name = "JUR")
    private String jur;

    @Column(name = "DSEQUENCE")
    private Integer dSequence;

    @Column(name = "UPDATED_DATE")
    private Date updatedDate;

    @Column(name = "CREATED_DATE")
    private Date createdDate;

}

Relationship between two table Document is the child table of Project,
I would like make one to relationship from Project side. From Document to project also fine

how can i map one to one relationship between tables ??

Upvotes: 0

Views: 40

Answers (2)

Srikanth Rajkumar
Srikanth Rajkumar

Reputation: 21

I don't have enough reputation to add a comment. But how is this a one-to-one mapping as having the column DID in the Document table proves that you can have multiple documents for the same project by having different DID. I am not sure if I am missing something here.

Upvotes: 0

Gal Shaboodi
Gal Shaboodi

Reputation: 764

  1. Document table should have the key columns of Project entity (pCode, bol etc..)

  2. Add this member on the Document class:

    @OneToOne
@JoinColumns({@JoinColumn(name = "pCode", referencedColumnName = "PROJECT_CODE"),
              @JoinColumn(name = "bol", referencedColumnName = "BOL"),
              @JoinColumn(name = "bols", referencedColumnName = "BOLS"),
              @JoinColumn(name = "eid", referencedColumnName = "EID")})
@MapsId("projectId")
private Project project;

Upvotes: 1

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