CODEWITHSUNDEEP
javamysqlhibernatejpaenums
Clown
Clown

Reputation: 291

How can I implement an Enum with JPA using separate Mysql Tables

I'm really new using JPA and still dont get how to achieve this, I would be glad to any suggestion or solution.

Mysql tables:

CREATE TABLE REAL_STATE_TYPES (
real_state_type_id INT(6) NOT NULL,
real_state_type VARCHAR(50) NOT NULL,
PRIMARY KEY (real_state_type_id)
);

CREATE TABLE REAL_STATES (
address VARCHAR(30) NOT NULL,
admin_id VARCHAR(15) NOT NULL,
real_state_type_id INT(6) NOT NULL,
block VARCHAR(3) NOT NULL,
internal_id INT(5) NOT NULL,
PRIMARY KEY (address, block, internal_id),
FOREIGN KEY (real_state_type_id) REFERENCES REAL_STATE_TYPES (real_state_type_id),
FOREIGN KEY (admin_id) REFERENCES ADMINS (admin_id)
);

so REAL_STATE has the id of REAL_STATE_TYPE, if I would want to keep this table's relationship how can I map them in the java code through JPA.

My java classes are:

import javax.persistence.Enumerated;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name= "real_state_types")
public class RealStateType implements Serializable{

    private static final long serialVersionUID = 5442745398170857199L;
    @Id
    @Column(name= "real_state_type_id ")
    private int realStateTypeId;
    @Column(name= "real_state_type")
    @Enumerated(EnumType.STRING)
    private RealStateEnum realStateType;
    @OneToOne(mappedBy = "realStateType", cascade = {CascadeType.ALL})
    private RealState realState;

And:

import javax.persistence.Column;
import javax.persistence.EmbeddedId;
import javax.persistence.Entity;
import javax.persistence.Enumerated;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Entity
@Table(name = "real_states")
public class RealState {
    @EmbeddedId
    private RealStateID realStateID;
    @Column(name = "real_state_type_id")
    private RealStateType realStateType;
    @ManyToOne
    @JoinColumn(name = "admin_id")
    private Admin admin;
}

Upvotes: 0

Views: 237

Answers (1)

tremendous7
tremendous7

Reputation: 776

to make it work i believe you need to 1. remove

@OneToOne(mappedBy = "realStateType", cascade = {CascadeType.ALL})
private RealState realState;

from RealStateType. 2. change

@Column(name = "real_state_type_id")
private RealStateType realStateType;

into

@JoinColumn(name = "real_state_type_id")
private RealStateType realStateType;

in RealState.

otherwise, if possible, i would just remove the RealStateType @Entity and just use

@Enumerated(EnumType.STRING)
@Column(name = "real_state_type", nullable = false)
private RealStateEnum realStateType;

in RealState

Upvotes: 1

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