Fremdschlüssel in der untergeordneten Tabelle ist null nach persistent @ OneToMany

Question

Ich versuche, Daten in Tabellen einzufügen, die @OneToMany Beziehung haben. Nachdem der Fremdschlüssel in der untergeordneten Tabelle beibehalten wurde, ist null.

Das Szenario ist: ein Employee kann viele Address es haben.

Address.java

@Entity 
@Table(name = "address") 
public class Address { 

    @Id 
    @GenericGenerator(name = "incgenerator", strategy = "increment") 
    @GeneratedValue(generator = "incgenerator") 
    private int id; 
    private String city; 
    private int zipCode; 

    @ManyToOne(cascade = CascadeType.ALL) 
    @JoinColumn(name = "empId") 
    private Employee employee; 

    // getters, setterd 
} 

Employee.java

@Entity 
@Table(name = "employee") 
public class Employee { 

    @Id 
    @GenericGenerator(name = "incgenerator", strategy = "increment") 
    @GeneratedValue(generator = "incgenerator") 
    private int id; 
    private String name; 

    @OneToMany(mappedBy = "employee", cascade = CascadeType.ALL) 
    private Set<Address> address; 

    // getters, setters 
} 

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?> 
<!DOCTYPE hibernate-configuration PUBLIC 
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 
<hibernate-configuration> 
<session-factory> 
    <property name="hbm2ddl.auto">update</property> 
    <property 
name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> 
    <property 
name="hibernate.connection.url">jdbc:mysql://localhost/retail</property> 
    <property name="hibernate.connection.username">root</property> 
    <property name="hibernate.connection.password"></property> 
    <property 
name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> 

    <property name="hibernate.show_sql">true</property> 
    <property name="hibernate.show_sql_format">true</property> 

    <mapping class="TestModel.Employee"/> 
    <mapping class="TestModel.Address"/> 
</session-factory> 
</hibernate-configuration> 

Test.java

public class Test { 

    public static void main(String[] args) { 

     Configuration c = new Configuration(); 
     c.configure("resources/hibernate.cfg.xml"); 

     SessionFactory sf = c.buildSessionFactory(); 
     Session s = sf.openSession(); 

     Transaction t = s.beginTransaction(); 

     Employee e = new Employee(); 
     e.setName("Farhaan"); 

     Address a = new Address(); 
     a.setCity("Kolonnawa"); 
     a.setZipCode(123); 

     Set<Address> aa = new HashSet(); 
     aa.add(a); 

     e.setAddress(aa); 

     s.saveOrUpdate(e); 

     t.commit(); 
    } 
} 

Answer 1

hinzufügen noch

a.setEmployee(e) 

in Ihrem Test. Sie müssen es explizit setzen