與連接表中的類型的單向關聯

Question

我有3個表格：Person - > Person_Address_Type {person_address_type_id（PK），person_id，address_id，type} - > Address。 Person_Address_Type用於指示Person和地址之間的關係類型。例如：

Mr. A has unique HOME addresses. 
Mr. A has one or many OFFICE addresses. 
Mr. A has one or many RELAXING addresses. 
... And other types of address may be added later. 

我怎樣才能讓映射與Hibernate有如下的java實體：

Person { 
    getHomeAddress(): Address; 
    getOfficeAddresses(): Address*; 
    getRelaxingAddresses(): Address*; 
} 

我知道有短暫的領域。但是，我們不能用瞬態做HQL查詢。我需要一個映射。 我該怎麼做？

感謝

Answer 1

你的映射應該是這樣的

表結構

CREATE TABLE `person` (
    `id_person` BIGINT(20) NOT NULL AUTO_INCREMENT, 
    `firstname` VARCHAR(50) NULL DEFAULT NULL, 
    `lastname` VARCHAR(50) NULL DEFAULT NULL, 
    `birth_date` DATE NULL DEFAULT NULL, 
    `cell_phone` VARCHAR(15) NULL DEFAULT NULL, 
    PRIMARY KEY (`id_person`) 
)ENGINE=InnoDB; 

CREATE TABLE `address_type` (
    `id_address_type` BIGINT(10) NOT NULL AUTO_INCREMENT, 
    `name` VARCHAR(50) NULL DEFAULT NULL, 
    PRIMARY KEY (`id_address_type`) 
)ENGINE=InnoDB; 

CREATE TABLE `address` (
    `id_address` BIGINT(10) NOT NULL AUTO_INCREMENT, 
    `fk_address_type`BIGINT(20) NULL DEFAULT NULL, 
    PRIMARY KEY (`id_address`), 
    CONSTRAINT `FK_ADDRESS_TYPE` FOREIGN KEY (`fk_address_type`) REFERENCES `address_type` (`id_address_type`), 
)ENGINE=InnoDB; 

CREATE TABLE `person_address` (
    `id_person_address` BIGINT(10) NOT NULL AUTO_INCREMENT, 
    `fk_person` BIGINT(20) NULL DEFAULT NULL, 
    `fk_address`BIGINT(20) NULL DEFAULT NULL,  
    PRIMARY KEY (`id_person_address`), 
    CONSTRAINT `FK_PERSON` FOREIGN KEY (`fk_person`) REFERENCES `person` (`id_person`), 
    CONSTRAINT `FK_ADDRESS` FOREIGN KEY (`fk_address`) REFERENCES `address` (`id_address`) 
)ENGINE=InnoDB; 

實體類

Person.java

@Entity 
@Table(name = "person",uniqueConstraints = { 
@UniqueConstraint(columnNames = "id_person")}) 
public class Person implements Serializable { 
    private static final long serialVersionUID = -1798070786993154676L; 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name = "id_person", unique = true, nullable = false) 
    private Integer id; 

    @OneToMany(cascade=CascadeType.ALL) 
    @JoinTable(name="person_address", joinColumns={@JoinColumn(name="fk_person", referencedColumnName="id_person")} 
    , inverseJoinColumns={@JoinColumn(name="fk_address", referencedColumnName="id_address")}) 
    private Set<Address> address; 

    // Getter and Setter methods 
} 

Address.java

@Entity 
@Table(name = "address", uniqueConstraints = { 
@UniqueConstraint(columnNames = "id_address")}) 
public class Address implements Serializable { 

    private static final long serialVersionUID = -6790693372846798580L; 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name = "id_address", unique = true, nullable = false) 
    private Integer addressId; 

    @OneToOne(mappedBy="address", cascade=CascadeType.ALL) 
    private AddressType addressType;  

    // Getter and Setter methods 
} 

AddressType.java

@Entity 
@Table(name="address_type",uniqueConstraints = { 
@UniqueConstraint(columnNames = "id_address_type")}) 
public class AddressType { 
      
    @Id 
    @Column(name="id_address_type", unique=true, nullable=false) 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private Long addressTypeId; 



    @OneToOne 
    @PrimaryKeyJoinColumn 
    private Address address;  

    // Getter and Setter methods 
} 

現在，當你調用getAddress()這將返回人l與Person相關的地址然後根據地址類型對該地址進行分組，即通過調用address.getAddressType().getName()方法。

您也可以從我的Hibernate的裸知識地址和地址類型實體之間@ManyToMany映射

Answer 2

，似乎關係表的樣式不是在Hibernate中直接支持。

最簡單的方法是創建Person_Address_Type的獨立意見，讓你有3個關係表，如：PERSON_HOME_ADDRESS，PERSON_OFFICE_ADDRESS，PERSON_RELAX_ADDRESS等

每個視圖只包含PERSON_ID和ADDRESS_ID

隨着這些意見，你可以做一個正常的ManyToMany/ManyToOne與JoinTable。

但是，如果要使用這些實體直接更新關係（取決於DBMS，某些DBMS允許通過視圖更新/插入），則此方法可能不起作用。

另一種方法是創建一個新的實體，如PersonAddressRelationship，它包含Person，Address和RelationshipType枚舉的引用。

然後，人員到地址中的三個關係不是直接映射的。相反，您根據您的映射addressRelationships填寫homeAddress,relaxAddresses和officeAddresses的@PostLoad方法的值。 （和@PrePersist方法更新homeAddress，relaxAddresses和officeAddresses的addressRelationships基礎太）

Answer 3

我剛纔發現@WhereJoinTable是這個（只是從理論上講，我還沒有在實踐中嘗試）