hibernate之關於使用串連表實現一對多關聯映射

標籤：one-to-many使用中間表進行關聯   一對多使用中間表進行關聯映射   

【Hibernate】之關於使用串連表實現一對多關聯映射

基於中間表實現的一對多的關聯映射，還是比較常見的。
Person(人)和Group(組)

Annotations配置

@Entity@Table(name="t_group")publicclass Group {    private Integer id;    private String name;    private Set<Person> persons=newHashSet<Person>();         @OneToMany    @JoinTable(name="t_p",joinColumns={@JoinColumn(name="g_id")},           inverseJoinColumns={@JoinColumn(name="p_id")})    public Set<Person> getPersons() {       returnpersons;    }    publicvoid setPersons(Set<Person> persons) {       this.persons = persons;    }    @Id    @GeneratedValue    public Integer getId() {       returnid;    }    publicvoid setId(Integer id) {       this.id = id;    }    @Column(name="g_name")    public String getName() {       returnname;    }    publicvoid setName(String name) {       this.name = name;    }}

@Entity@Table(name="p_person")publicclass Person {    private Integer id;    private String name;    private Integer age;    @Id    @GeneratedValue    public Integer getId() {       returnid;    }    publicvoid setId(Integer id) {       this.id = id;    }    @Column(name="p_name")    public String getName() {       returnname;    }    publicvoid setName(String name) {       this.name = name;    }    @Column(name="p_age")    public Integer getAge() {       returnage;    }    publicvoid setAge(Integer age) {       this.age = age;    }}

XML配置

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/HibernateMapping DTD 3.0//EN"    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><hibernate-mapping package="csg.hibernate.entity">    <class name="Group" table="t_group">       <id name="id">           <column name="id"/>           <generator class="native" />       </id>       <property name="name" />       <set name="persons" table="t_p">           <key column="g_id"/>           <many-to-many column="p_id" class="Person" unique="true" />       </set>    </class></hibernate-mapping>

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/HibernateMapping DTD 3.0//EN"    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><hibernate-mapping package="csg.hibernate.entity">    <class name="Person" table="t_person">       <id name="id">           <column name="id"/>           <generator class="native" />       </id>       <property name="name" />       <property name="age" />    </class></hibernate-mapping>

在一對多的中間表映射中，Hibernate自動會轉化為多對多來處理！

hibernate之關於使用串連表實現一對多關聯映射