Hibernate about using join tables to implement a one-to-many association mapping

"Hibernate" about using a join table to implement a one -to-many association mapping

A one-to-many association mapping based on an intermediate table is still more common.

Person (people) and group (group)

Annotations Configuration

@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 () &NBSP;{&NBSP;&Nbsp;     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")   &nbsP; public integer getage ()  {       returnage;     }    publicvoid setage (integer age)  {        this.age = age;    }}

XML configuration

<?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>
<?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>

In a one-to-many intermediate table mapping, Hibernate automatically translates to many-to-many processing!

This article from "Promise always attached to the small wood 、、、" blog, please be sure to keep this source http://1936625305.blog.51cto.com/6410597/1569047
Hibernate about using join tables to implement a one-to-many association mapping