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Hibernate 一对多连接表单向关联 |
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一、模型介绍 |
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一个人(Person)对应多个地址(Address),比如家庭地址、公司地址。 |
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二、实体(省略getter、setter方法) |
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public class Person1ntab { |
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private int personid; |
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private String name; |
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private int age; |
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private Set addresses=new HashSet(); |
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public class Address1nfk implements Serializable { |
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private int addressid; |
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private String addressdetail; |
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三、表模型 |
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mysql> desc join_1ntab; |
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+-----------+---------+------+-----+---------+-------+ |
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| Field | Type | Null | Key | Default | Extra | |
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+-----------+---------+------+-----+---------+-------+ |
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| personid | int(11) | NO | PRI | | | |
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| addressid | int(11) | NO | PRI | | | |
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+-----------+---------+------+-----+---------+-------+ |
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mysql> desc person_1ntab; |
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+----------+--------------+------+-----+---------+----------------+ |
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| Field | Type | Null | Key | Default | Extra | |
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+----------+--------------+------+-----+---------+----------------+ |
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| personid | int(11) | NO | PRI | NULL | auto_increment | |
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| name | varchar(255) | YES | | NULL | | |
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| age | int(11) | YES | | NULL | | |
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+----------+--------------+------+-----+---------+----------------+ |
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mysql> desc address_1ntab; |
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+---------------+--------------+------+-----+---------+----------------+ |
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| Field | Type | Null | Key | Default | Extra | |
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+---------------+--------------+------+-----+---------+----------------+ |
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| addressid | int(11) | NO | PRI | NULL | auto_increment | |
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| addressdetail | varchar(255) | YES | | NULL | | |
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+---------------+--------------+------+-----+---------+----------------+ |
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四、生成的SQL脚本 |
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/* Formatted on 2007/08/21 10:58 (QP5 v5.50) */ |
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CREATE TABLE `address_1ntab` ( |
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`addressid` int(11) NOT NULL auto_increment, |
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`addressdetail` varchar(255) default NULL, |
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PRIMARY KEY (`addressid`) |
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) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=gbk; |
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/* Formatted on 2007/08/21 10:58 (QP5 v5.50) */ |
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CREATE TABLE `join_1ntab` ( |
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`personid` int(11) NOT NULL, |
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`addressid` int(11) NOT NULL, |
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PRIMARY KEY (`personid`,`addressid`), |
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UNIQUE KEY `addressid` (`addressid`), |
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KEY `FK6B6078C3C8DF5BFF` (`personid`), |
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KEY `FK6B6078C3C2B11347` (`addressid`), |
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CONSTRAINT `FK6B6078C3C2B11347` FOREIGN KEY (`addressid`) REFERENCES `address_1ntab` (`addressid`), |
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CONSTRAINT `FK6B6078C3C8DF5BFF` FOREIGN KEY (`personid`) REFERENCES `person_1ntab` (`personid`) |
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) ENGINE=InnoDB DEFAULT CHARSET=gbk; |
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/* Formatted on 2007/08/21 10:58 (QP5 v5.50) */ |
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CREATE TABLE `person_1ntab` ( |
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`personid` int(11) NOT NULL auto_increment, |
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`name` varchar(255) default NULL, |
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`age` int(11) default NULL, |
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PRIMARY KEY (`personid`) |
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) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=gbk; |
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五、映射方法 |
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<hibernate-mapping> |
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<class name="com.lavasoft.dx._1_n_tab.Person1ntab" table="PERSON_1ntab"> |
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<id name="personid"> |
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<generator class="identity"/> |
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</id> |
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<property name="name"/> |
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<property name="age"/> |
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<!--映射集合属性,join_1ntab是连接表表名--> |
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<set name="addresses" |
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table="join_1ntab" |
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> |
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<!--“column="personid"”确定PERSON_1ntab表关联到连接表的外键列名--> |
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<key column="personid"/> |
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<!--“column="addressid"”关联PERSON_1ntab表的Address1ntab对象的id在连接表中的列名--> |
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<!--“unique="true"表示1-N,Person1ntab是1,Address1ntab是多”--> |
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<many-to-many |
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column="addressid" |
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unique="true" |
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class="com.lavasoft.dx._1_n_tab.Address1ntab"/> |
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</set> |
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</class> |
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</hibernate-mapping> |
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<hibernate-mapping> |
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<class name="com.lavasoft.dx._1_n_tab.Address1ntab" table="ADDRESS_1ntab"> |
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<id name="addressid"> |
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<generator class="identity"/> |
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</id> |
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<property name="addressdetail"/> |
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</class> |
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</hibernate-mapping> |
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六、测试方法 |
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public class Test_1ntab { |
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public static void main(String[] args){ |
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Address1ntab add1=new Address1ntab(); |
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Address1ntab add2=new Address1ntab(); |
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Address1ntab add3=new Address1ntab(); |
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Person1ntab p1=new Person1ntab(); |
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Person1ntab p2=new Person1ntab(); |
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add1.setAddressdetail("郑州市经三路"); |
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add2.setAddressdetail("合肥市宿州路"); |
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add3.setAddressdetail("北京市长安路"); |
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p1.setName("wang"); |
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p1.setAge(30); |
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p2.setName("lee"); |
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p2.setAge(50); |
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p1.getAddresses().add(add1); |
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p1.getAddresses().add(add2); |
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//p2.getAddresses().add(add2); |
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p2.getAddresses().add(add3); |
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Session session= HibernateUtil.getCurrentSession(); |
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Transaction tx=session.beginTransaction(); |
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session.save(add1); |
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session.save(add2); |
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session.save(add3); |
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session.save(p1); |
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session.save(p2); |
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tx.commit(); |
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HibernateUtil.closeSession(); |
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} |
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} |
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七、测试结果 |
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1) :正常保存. |
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session.save(add1); |
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session.save(add2); |
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session.save(add3); |
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session.save(p1); |
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session.save(p2); |
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Hibernate: insert into PERSON_1nfk (name, age) values (?, ?) |
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Hibernate: insert into ADDRESS_1nfk (addressdetail) values (?) |
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Hibernate: insert into ADDRESS_1nfk (addressdetail) values (?) |
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Hibernate: update ADDRESS_1nfk set personid=? where addressid=? |
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Hibernate: update ADDRESS_1nfk set personid=? where addressid=? |
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