hibernate---一对一单向外键关联--annotation (重要!!!)
1. 生成wife.java:
package com.bjsxt.hibernate; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; @Entity public class Wife { private int id; private String name; @Id @GeneratedValue 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; } }
2. 生成husband.java, 指定:
@OneToOne @JoinColumn(name="wifeId")
package com.bjsxt.hibernate; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.OneToOne; @Entity public class Husband { private int id; private String name; private Wife wife; @Id @GeneratedValue public int getId() { return id; } public String getName() { return name; } @OneToOne @JoinColumn(name="wifeId") public Wife getWife() { return wife; } public void setId(int id) { this.id = id; } public void setName(String name) { this.name = name; } public void setWife(Wife wife) { this.wife = wife; } }
3. hibernate.cfg.xml里设定:
<?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="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost/hibernate</property> <property name="connection.username">root</property> <property name="connection.password">linda0213</property> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <!-- <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property> <property name="connection.url">jdbc:oracle:thin:@localhost:1521:SXT</property> <property name="connection.username">scott</property> <property name="connection.password">tiger</property> <property name="dialect">org.hibernate.dialect.OracleDialect</property> --> <!-- JDBC connection pool (use the built-in) --> <property name="connection.pool_size">1</property> <!-- Enable Hibernate's automatic session context management --> <property name="current_session_context_class">thread</property> <!-- Disable the second-level cache --> <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> <!-- Echo all executed SQL to stdout --> <property name="show_sql">true</property> <property name="format_sql">true</property> <!-- Drop and re-create the database schema on startup <property name="hbm2ddl.auto">update</property> --> <!-- --> <!-- <mapping resource="com/bjsxt/hibernate/Student.hbm.xml"/> --> <!-- <mapping resource="com/bjsxt/hibernate/StuIdCard.hbm.xml"/> --> <mapping class="com.bjsxt.hibernate.Husband"/> <mapping class="com.bjsxt.hibernate.Wife"/> </session-factory> </hibernate-configuration>
测试文件:HibernateORMappingTest.java:
package com.bjsxt.hibernate; import java.util.Date; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.AnnotationConfiguration; import org.hibernate.tool.hbm2ddl.SchemaExport; import org.junit.AfterClass; import org.junit.BeforeClass; import org.junit.Test; public class HibernateORMappingTest { private static SessionFactory sessionFactory; //@BeforeClass public static void beforeClass() { sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory(); } //@AfterClass public static void afterClass() { sessionFactory.close(); } @Test public void testSchemaExport() { new SchemaExport(new AnnotationConfiguration().configure()).create(false, true); } public static void main(String[] args) { beforeClass(); } }
5. run as-junit test, 查看结果, 成功生成onetoone的两个表:
08:36:00,681 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:303 - create table Husband ( id integer not null auto_increment, name varchar(255), wifeId integer, primary key (id) ) 08:36:00,850 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:303 - create table Wife ( id integer not null auto_increment, name varchar(255), primary key (id) ) 08:36:00,937 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:303 - alter table Husband add index FKAEEA401B109E78ED (wifeId), add constraint FKAEEA401B109E78ED foreign key (wifeId) references Wife (id) 08:36:01,538 INFO org.hibernate.tool.hbm2ddl.SchemaExport:196 - schema export complete