IdCard.hbm.xml
<?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.hibernate.c_onetoone"> <class name="IdCard" table="t_card"> <id name="id" > <generator class="native"/> </id> <property name="number"/> <many-to-one name="person" class="Person" column="pserson_id" unique="true"></many-to-one> </class> </hibernate-mapping>
1、一对一关系中存在两张表,id card表有外键,所以使用many-to-one 来对应
2、指定class,外键名称column="pserson_id",唯一性unique="true"
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Person.hbm.xml
<?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.hibernate.c_onetoone"> <class name="Person" table="t_person"> <id name="id" > <generator class="native"/> </id> <property name="name"/> <one-to-one name="idCard" ></one-to-one> </class> </hibernate-mapping>
1、一对一关系使用one-to-one 因为这张表无外键
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Person.java
public class Person { int id; String name; IdCard idCard; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public IdCard getIdCard() { return idCard; } public void setIdCard(IdCard idCard) { this.idCard = idCard; } @Override public String toString() { return "Person [id=" + id + ", name=" + name + "]"; } }
IdCard.java
public class IdCard { int id; String number; Person person; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getNumber() { return number; } public void setNumber(String number) { this.number = number; } public Person getPerson() { return person; } public void setPerson(Person person) { this.person = person; } @Override public String toString() { return "IdCard [id=" + id + ", number=" + number + "]"; } }
app.java:
public class APP { static SessionFactory sessionFactory=null; static{ sessionFactory =new Configuration().configure().addClass(Person.class).addClass(IdCard.class).buildSessionFactory(); } @Test public void setApp() { Session sess= sessionFactory.openSession(); Transaction ts=null; // ts=sess.beginTransaction(); Person person1=new Person(); person1.setName("p1"); IdCard idCard1=new IdCard(); idCard1.setNumber("000001"); Person person2=new Person(); person2.setName("p2"); IdCard idCard2=new IdCard(); idCard2.setNumber("000002"); Person person3=new Person(); person3.setName("p3"); IdCard idCard3=new IdCard(); idCard3.setNumber("000002"); // person1.setIdCard(idCard1); person2.setIdCard(idCard2); person3.setIdCard(idCard3); idCard1.setPerson(person1); idCard2.setPerson(person2); idCard3.setPerson(person3); // sess.save(person1); sess.save(idCard1); sess.save(person2); sess.save(idCard2); sess.save(person3); sess.save(idCard3); ts.commit(); sess.close(); }
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1、一对一关系中会生成两张表,一张有外键,一张无外键
2、有外键的一方用many-to-one ,然后用唯一性进行约束即可
3、无外键一方使用one-to-one
时间: 2024-10-20 13:24:24