hibernate one-to-one foreign key association

1. Create entity class

Java code

package com.wr.hibernate.entity;  
  
public class Department {  
  
    private int deptId;  
    private String deptName;  
    private Manager mgr;  
  
    public int getDeptId() {  
        return deptId;  
    }  
  
    public Manager getMgr() {  
        return mgr;  
    }  
  
    public void setMgr(Manager mgr) {  
        this.mgr = mgr;  
    }  
  
    public void setDeptId(int deptId) {  
        this.deptId = deptId;  
    }  
  
    public String getDeptName() {  
        return deptName;  
    }  
  
    public void setDeptName(String deptName) {  
        this.deptName = deptName;  
    }  
  
    @Override  
    public String toString() {  
        return "Department [deptId=" + deptId + ", deptName=" + deptName + "]";  
    }  
  
}

Java code

package com.wr.hibernate.entity;  
  
public class Manager {  
  
    private int mgrId;  
    private String mgrName;  
    private Department dept;  
  
    public int getMgrId() {  
        return mgrId;  
    }  
  
    public void setMgrId(int mgrId) {  
        this.mgrId = mgrId;  
    }  
  
    public String getMgrName() {  
        return mgrName;  
    }  
  
    public void setMgrName(String mgrName) {  
        this.mgrName = mgrName;  
    }  
  
    public Department getDept() {  
        return dept;  
    }  
  
    public void setDept(Department dept) {  
        this.dept = dept;  
    }  
  
    @Override  
    public String toString() {  
        return "Manager [mgrId=" + mgrId + ", mgrName=" + mgrName + ", dept=" + dept + "]";  
    }  
  
}

2. Create POJO mapping file

Xml code

<?xml version="1.0"?>  
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"  
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">  
  
<hibernate-mapping package="com.wr.hibernate.entity">  
  
    <class name="Department" table="department" dynamic-insert="true">  
  
        <id name="deptId" type="java.lang.Integer">  
            <column name="dept_id" />  
            <generator class="native"></generator>  
        </id>  
  
        <property name="deptName" type="java.lang.String">  
            <column name="dept_name" />  
        </property>  
          
        <many-to-one name="mgr" class="Manager">  
            <column name="mgr_id" unique="true"></column>  
        </many-to-one>  
          
          
    </class>  
  
</hibernate-mapping>

Xml code

<?xml version="1.0"?>  
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"  
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">  
  
<hibernate-mapping package="com.wr.hibernate.entity">  
  
    <class name="Manager" table="manager" dynamic-insert="true">  
  
        <id name="mgrId" type="java.lang.Integer">  
            <column name="mgr_id" />  
            <generator class="native"></generator>  
        </id>  
  
        <property name="mgrName" type="java.lang.String">  
            <column name="mgr_name" />  
        </property>  
          
        <one-to-one name="dept" class="Department" property-ref="mgr">  
        </one-to-one>  
  
    </class>  
  
</hibernate-mapping>