ManyToMany 会产生一个中间表，如何对中间表加入其它字段 有什么方法么？

[shaodong-hub]

例如下面代码，中间表SYSTEM_USER_ROLE 表只会生成 "mid_user_id" 和 "mid_role_id" 两个字段作为联合主键， 如何在中间表中加入其它字段，如：“lastModifiedDate”，“createDate”，“version” 等

@ManyToMany(
            targetEntity = ManyToManyRoleDO.class,
            cascade = {CascadeType.REFRESH},
            fetch = FetchType.EAGER
    )
    @JoinTable(
            name = SYSTEM_USER_ROLE,
            joinColumns = {@JoinColumn(name = "mid_user_id", referencedColumnName = "user_id")},
            inverseJoinColumns = {@JoinColumn(name = "mid_role_id", referencedColumnName = "role_id")}
    )
    @JsonManagedReference
    private Set<ManyToManyRoleDO> roles;

[zhangzhenhuajack]

上面只是一种简便方法，创建三个实体，中间表分别用两个ManyToOne

[zhangzhenhuajack]

https://docs.jboss.org/hibernate/orm/5.2/userguide/html_single/Hibernate_User_Guide.html#associations-one-to-one

[zhangzhenhuajack]

@Entity(name = "Person")
public static class Person implements Serializable {

    @Id
    @GeneratedValue
    private Long id;

    @NaturalId
    private String registrationNumber;

    @OneToMany(mappedBy = "person", cascade = CascadeType.ALL, orphanRemoval = true)
    private List<PersonAddress> addresses = new ArrayList<>();

    public Person() {
    }

    public Person(String registrationNumber) {
        this.registrationNumber = registrationNumber;
    }

    public Long getId() {
        return id;
    }

    public List<PersonAddress> getAddresses() {
        return addresses;
    }

    public void addAddress(Address address) {
        PersonAddress personAddress = new PersonAddress( this, address );
        addresses.add( personAddress );
        address.getOwners().add( personAddress );
    }

    public void removeAddress(Address address) {
        PersonAddress personAddress = new PersonAddress( this, address );
        address.getOwners().remove( personAddress );
        addresses.remove( personAddress );
        personAddress.setPerson( null );
        personAddress.setAddress( null );
    }

    @Override
    public boolean equals(Object o) {
        if ( this == o ) {
            return true;
        }
        if ( o == null || getClass() != o.getClass() ) {
            return false;
        }
        Person person = (Person) o;
        return Objects.equals( registrationNumber, person.registrationNumber );
    }

    @Override
    public int hashCode() {
        return Objects.hash( registrationNumber );
    }
}

@Entity(name = "PersonAddress")
public static class PersonAddress implements Serializable {

    @Id
    @ManyToOne
    private Person person;

    @Id
    @ManyToOne
    private Address address;

    public PersonAddress() {
    }

    public PersonAddress(Person person, Address address) {
        this.person = person;
        this.address = address;
    }

    public Person getPerson() {
        return person;
    }

    public void setPerson(Person person) {
        this.person = person;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    @Override
    public boolean equals(Object o) {
        if ( this == o ) {
            return true;
        }
        if ( o == null || getClass() != o.getClass() ) {
            return false;
        }
        PersonAddress that = (PersonAddress) o;
        return Objects.equals( person, that.person ) &&
                Objects.equals( address, that.address );
    }

    @Override
    public int hashCode() {
        return Objects.hash( person, address );
    }
}

@Entity(name = "Address")
public static class Address implements Serializable {

    @Id
    @GeneratedValue
    private Long id;

    private String street;

    @Column(name = "`number`")
    private String number;

    private String postalCode;

    @OneToMany(mappedBy = "address", cascade = CascadeType.ALL, orphanRemoval = true)
    private List<PersonAddress> owners = new ArrayList<>();

    public Address() {
    }

    public Address(String street, String number, String postalCode) {
        this.street = street;
        this.number = number;
        this.postalCode = postalCode;
    }

    public Long getId() {
        return id;
    }

    public String getStreet() {
        return street;
    }

    public String getNumber() {
        return number;
    }

    public String getPostalCode() {
        return postalCode;
    }

    public List<PersonAddress> getOwners() {
        return owners;
    }

    @Override
    public boolean equals(Object o) {
        if ( this == o ) {
            return true;
        }
        if ( o == null || getClass() != o.getClass() ) {
            return false;
        }
        Address address = (Address) o;
        return Objects.equals( street, address.street ) &&
                Objects.equals( number, address.number ) &&
                Objects.equals( postalCode, address.postalCode );
    }

    @Override
    public int hashCode() {
        return Objects.hash( street, number, postalCode );
    }
}
CREATE TABLE Address (
    id BIGINT NOT NULL ,
    number VARCHAR(255) ,
    postalCode VARCHAR(255) ,
    street VARCHAR(255) ,
    PRIMARY KEY ( id )
)

CREATE TABLE Person (
    id BIGINT NOT NULL ,
    registrationNumber VARCHAR(255) ,
    PRIMARY KEY ( id )
)

CREATE TABLE PersonAddress (
    person_id BIGINT NOT NULL ,
    address_id BIGINT NOT NULL ,
    PRIMARY KEY ( person_id, address_id )
)

ALTER TABLE Person
ADD CONSTRAINT UK_23enodonj49jm8uwec4i7y37f
UNIQUE (registrationNumber)

ALTER TABLE PersonAddress
ADD CONSTRAINT FK8b3lru5fyej1aarjflamwghqq
FOREIGN KEY (person_id) REFERENCES Person

ALTER TABLE PersonAddress
ADD CONSTRAINT FK7p69mgialumhegyl4byrh65jk
FOREIGN KEY (address_id) REFERENCES Address