标签：style blog class code java ext
1、项目结构：
1.1、场景说明: 一个订单，包含多个产品
1.2、类文件：
Order.java
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package
com.rhythmk.model;import java.util.Date;public class Order { public
int getOrderID() { return
orderID; } public
void setOrderID(int
orderID) { this.orderID = orderID; } public
String getName() { return
Name; } public
void setName(String name) { Name = name; } public
double getSumMoney() { return
SumMoney; } public
void setSumMoney(double
sumMoney) { SumMoney = sumMoney; } public
Date getCreateDate() { return
createDate; } public
void setCreateDate(Date createDate) { this.createDate = createDate; } private
int orderID; private
String Name; private
double SumMoney; @Override public
String toString() { return
"Order [orderID=" + orderID + ", Name="
+ Name + ", SumMoney=" + SumMoney + ", createDate="
+ createDate + "]"; } private
Date createDate; } |
order.hbm.xml
<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="com.rhythmk.model.Order" table="t_order"> <id name="orderID" type="int"> <column name="orderID" /> <generator class="native" /> </id> <property name="Name" type="string"> <column name="Name" not-null="true" /> </property> <property name="SumMoney" type="double"></property> <property name="createDate" type="timestamp"> <column name="createDate" not-null="true" /> </property> </class> </hibernate-mapping>
Product.java
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package
com.rhythmk.model;public class Product { public
int getProductID() { return
productID; } public
void setProductID(int
productID) { this.productID = productID; } public
String getProductName() { return
productName; } public
void setProductName(String productName) { this.productName = productName; } private
int productID; private
String productName; public
Order getOrder() { return
order; } public
void setOrder(Order order) { this.order = order; } private
Order order ; @Override public
String toString() { return
"Product [productID=" + productID + ", productName=" + productName + ", order="
+ order + "]"; } } |
product.hbm.xml
<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="com.rhythmk.model.Product" table="t_product"> <id name="productID" type="int"> <column name="productID" /> <generator class="native" /> </id> <property name="productName" type="string"> <column name="productName" /> </property> <many-to-one name="order" column="orderID"></many-to-one> </class> </hibernate-mapping>
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"> <!-- Generated by MyEclipse Hibernate Tools. --> <hibernate-configuration> <session-factory> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <property name="connection.url">jdbc:mysql://localhost:3306/hibernate_demo</property> <property name="connection.username">root</property> <property name="connection.password">wangkun</property> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="myeclipse.connection.profile">com.mysql.jdbc.Driver</property> <!--是否在后台显示Hibernate用到的SQL语句，开发时设置为true，便于差错，程序运行时可以在Eclipse的控制台显示Hibernate的执行Sql语句。项目部署后可以设置为false，提高运行效率 --> <property name="hibernate.show_sql">true </property> <property name="hibernate.hbm2ddl.auto">update</property> <mapping resource="com/rhythmk/model/user.hbm.xml" /> <mapping resource="com/rhythmk/model/product.hbm.xml" /> <mapping resource="com/rhythmk/model/order.hbm.xml" /> </session-factory> </hibernate-configuration>
1.3 、结论：
在Many方 定义XML配置 ：
<many-to-one name="order" column="orderID"></many-to-one>
写入数据调用session.save方法跟单表保存基本一致。
读取数据：获取Many对象，默认 One对象都是以延迟加载模式进行加载。
不论是删除 Many ,还是删除 One 对象 都只删除本身数据 ，并非删除全部主从数据，如果删除One对象，一旦Many还有关联One的对象的存在，则将抛出异常。见(test04_del)
1.4 、测试验证:
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@Test public
void test02_add() { Session session = null; try
{ session = HibernateUtil.getSessionFactory().openSession(); session.beginTransaction(); Order order = new
Order(); order.setCreateDate(new
Date()); order.setName("订单一"); order.setSumMoney(12); session.save(order); Product p1 = new
Product(); p1.setOrder(order); p1.setProductName("产品1"); session.save(p1); Product p2 = new
Product(); p2.setOrder(order); p2.setProductName("产品2"); session.save(p2); session.getTransaction().commit(); } catch
(Exception e) { e.printStackTrace(); } finally
{ if
(session != null) session.close(); } } |
输出：
Hibernate: insert into t_order (Name, SumMoney, createDate) values (?, ?,
?)
Hibernate: insert into t_product (productName, orderID) values (?,
?)
Hibernate: insert into t_product (productName, orderID) values (?, ?)
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@Testpublic void test03_load() { Session session = null; try
{ session = HibernateUtil.getSessionFactory().openSession(); Order order = (Order) session.load(Order.class, 1); System.out.println(order); System.out.println("-----------Read Product-----------"); Product product = (Product) session.load(Product.class, 1); System.out.println("-----------Print Product-----------"); System.out.println(product); System.out.println("-----------Read Order-----------"); System.out.println(product.getOrder().getName()); } catch
(Exception e) { e.printStackTrace(); } finally
{ if
(session != null) session.close(); }} |
输出：
Hibernate: select order0_.orderID as orderID1_0_0_, order0_.Name as
Name2_0_0_, order0_.SumMoney as SumMoney3_0_0_, order0_.createDate as
createDa4_0_0_ from t_order order0_ where order0_.orderID=?
Order [orderID=1,
Name=订单一, SumMoney=12.0, createDate=2014-05-02 15:24:02.0]
-----------Read
Product-----------
-----------Print Product-----------
Hibernate: select
product0_.productID as productI1_1_0_, product0_.productName as productN2_1_0_,
product0_.orderID as orderID3_1_0_ from t_product product0_ where
product0_.productID=?
Product [productID=1, productName=产品1, order=Order
[orderID=1, Name=订单一, SumMoney=12.0, createDate=2014-05-02
15:24:02.0]]
-----------Read Order-----------
订单一
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@Testpublic void test04_Get() { Session session = null; try
{ session = HibernateUtil.getSessionFactory().openSession(); System.out.println("-----------Read Product-----------"); Product product = (Product) session.get(Product.class, 1); System.out.println("-----------Print Product-----------"); System.out.println(product); System.out.println("-----------Read Order-----------"); System.out.println(product.getOrder().getName()); } catch
(Exception e) { e.printStackTrace(); } finally
{ if
(session != null) session.close(); }} |
输出：
-----------Read Product-----------
Hibernate: select product0_.productID
as productI1_1_0_, product0_.productName as productN2_1_0_, product0_.orderID as
orderID3_1_0_ from t_product product0_ where
product0_.productID=?
-----------Print Product-----------
Hibernate:
select order0_.orderID as orderID1_0_0_, order0_.Name as Name2_0_0_,
order0_.SumMoney as SumMoney3_0_0_, order0_.createDate as createDa4_0_0_ from
t_order order0_ where order0_.orderID=?
Product [productID=1,
productName=产品1, order=Order [orderID=1, Name=订单一, SumMoney=12.0,
createDate=2014-05-02 15:24:02.0]]
-----------Read
Order-----------
订单一
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@Testpublic void test04_Del() { Session session = null; try
{ session = HibernateUtil.getSessionFactory().openSession(); session.beginTransaction(); /* Product product = (Product) session.get(Product.class, 1); session.delete(product); 输出： Hibernate: select product0_.productID as productI1_1_0_, product0_.productName as productN2_1_0_, product0_.orderID as orderID3_1_0_ from t_product product0_ where product0_.productID=? Hibernate: delete from t_product where productID=? */ Order order = (Order) session.get(Order.class, 3); session.delete(order); session.getTransaction().commit(); } catch
(Exception e) { e.printStackTrace(); } finally
{ if
(session != null) session.close(); }} |
输出：
Hibernate: select order0_.orderID as orderID1_0_0_, order0_.Name as
Name2_0_0_, order0_.SumMoney as SumMoney3_0_0_, order0_.createDate as
createDa4_0_0_ from t_order order0_ where order0_.orderID=?
Hibernate: delete
from t_order where orderID=?
org.hibernate.exception.ConstraintViolationException:
could not execute statement
at
org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:72)
at
org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at
org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:126)
at
org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:112)
at
org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:190)
-------------------------------------------------OneToMany----------------------------------------------------------------------------
>>> OneToMany 单相关联
2.1
需求背景：
每个人都有很多标签：
在User 类中添加：
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public Set<Tag> getTags() { return
tags;}public void setTags(Set<Tag> tags) { this.tags = tags;}private
Set<Tag> tags; |
同时 添加 Tag类：
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package
com.rhythmk.model;public class Tag { public
Integer getTagId() { return
tagId; } public
void setTagId(Integer tagId) { this.tagId = tagId; } public
String getTagTitle() { return
tagTitle; } public
void setTagTitle(String tagTitle) { this.tagTitle = tagTitle; } public
Integer getUserID() { return
userID; } @Override public
String toString() { return
"Tag [tagId=" + tagId + ", tagTitle="
+ tagTitle + ", userID=" + userID + "]"; } public
void setUserID(Integer userID) { this.userID = userID; }private
Integer tagId; private
String tagTitle; private
Integer userID;} |
添加User对应XML配置：
<set name="tags"> <key column="userID"></key> <!-- 此处需要配置完成的类别--> <one-to-many class="com.rhythmk.model.Tag" /> </set>
注意：此处 one-to-many 对应的 class 需要填写类的全路径名称
2.2 验证：
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@Test public
void test01_add() { Session session = null; try
{ session = HibernateUtil.getSessionFactory().openSession(); session.beginTransaction(); Tag t1 = new
Tag(); t1.setTagTitle("tag1"); Tag t2 = new
Tag(); t2.setTagTitle("tag2"); Set<Tag> tags = new
HashSet<Tag>(); tags.add(t1); tags.add(t2); User entity = new
User(); entity.setUserName("张飞2222"); entity.setCreateTime(new
Date()); entity.setTags(tags); session.save(t1); session.save(t2); session.save(entity); session.getTransaction().commit(); } catch
(Exception e) { e.printStackTrace(); } finally
{ if
(session != null) session.close(); } } |
输出：
Hibernate: insert into t_tag (tagTitle) values (?)
Hibernate: insert into
t_tag (tagTitle) values (?)
Hibernate: insert into t_user (userName,
createTime) values (?, ?)
Hibernate: update t_tag set userID=? where
tagId=?
Hibernate: update t_tag set userID=? where tagId=?
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@Test public
void test02_get() { Session session = null; try
{ session = HibernateUtil.getSessionFactory().openSession(); session.beginTransaction(); System.err.println("------01 -----------"); User entity = (User) session.get(User.class, 6); System.err.println("------02 -----------"); for
(Tag t : entity.getTags()) { System.out.println(t); } session.getTransaction().commit(); } catch
(Exception e) { e.printStackTrace(); } finally
{ if
(session != null) session.close(); } } |
输出：
------01 -----------
Hibernate: select user0_.userID as userID1_3_0_,
user0_.userName as userName2_3_0_, user0_.createTime as createTi3_3_0_ from
t_user user0_ where user0_.userID=?
------02 -----------
Hibernate: select
tags0_.userID as userID3_3_0_, tags0_.tagId as tagId1_2_0_, tags0_.tagId as
tagId1_2_1_, tags0_.tagTitle as tagTitle2_2_1_ from t_tag tags0_ where
tags0_.userID=?
Tag [tagId=2, tagTitle=tag1, userID=null]
Tag [tagId=3,
tagTitle=tag2, userID=null]
>>> OneToMany 双相关联
背景：一个标签下有多少人
调整原标签代码：
<set name="users"> <key column="tagId"></key> <!-- 此处需已在hibernate-mapping 上配置了 类包名--> <one-to-many class="User" /> </set>
one-to-many class仅填写类名 现将包名调整到 hibernate-mapping属性上 如：
<hibernate-mapping package="com.rhythmk.model">
调整 Tag.java,添加：
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public Set<User> getUsers() { return
users;}public void setUsers(Set<User> users) { this.users = users;}private
Set<User> users; |
测试：
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@Test public
void test01_add() { Session session = null; try
{ session = HibernateUtil.getSessionFactory().openSession(); session.beginTransaction(); Tag t1 = new
Tag(); t1.setTagTitle("tag1"); Tag t2 = new
Tag(); t2.setTagTitle("tag2"); Set<Tag> tags = new
HashSet<Tag>(); tags.add(t1); tags.add(t2); User u1 = new
User(); u1.setUserName("张飞2222"); u1.setCreateTime(new
Date()); u1.setTags(tags); User u2 = new
User(); u2.setUserName("张飞2333332"); u2.setCreateTime(new
Date()); u2.setTags(tags); Set<User> users = new
HashSet<User>(); users.add(u1); users.add(u2); t1.setUsers(users); t2.setUsers(users); session.save(t1); session.save(t2); session.save(u1); session.save(u2); session.getTransaction().commit(); } catch
(Exception e) { e.printStackTrace(); } finally
{ if
(session != null) session.close(); } } |
输出：
Hibernate: insert into t_tag (tagTitle) values (?)
Hibernate: insert into
t_tag (tagTitle) values (?)
Hibernate: insert into t_user (userName,
createTime) values (?, ?)
Hibernate: insert into t_user (userName,
createTime) values (?, ?)
Hibernate: update t_user set tagId=? where
userID=?
Hibernate: update t_user set tagId=? where userID=?
Hibernate:
update t_user set tagId=? where userID=?
Hibernate: update t_user set tagId=?
where userID=?
Hibernate: update t_tag set userID=? where
tagId=?
Hibernate: update t_tag set userID=? where tagId=?
Hibernate:
update t_tag set userID=? where tagId=?
Hibernate: update t_tag set userID=?
where tagId=?
注意：此处因为在提交事务过程中 Tag 以及User都相互影响变化，故出现12条SQL。
在实际项目中 我们并非需要 One 跟 Many都同时去维护数据，故引入 inverse，当inverse="true" 则不去维护对应关系，现修改User.hbm.xml 如下：
<set name="tags" lazy="extra" inverse="true"> <key column="userID"></key> <!-- 此处需要配置完成的类别--> <one-to-many class="com.rhythmk.model.Tag" /> </set>
执行测试输出：
Hibernate: insert into t_tag (tagTitle) values (?)
Hibernate: insert into
t_tag (tagTitle) values (?)
Hibernate: insert into t_user (userName,
createTime) values (?, ?)
Hibernate: insert into t_user (userName,
createTime) values (?, ?)
Hibernate: update t_user set tagId=? where
userID=?
Hibernate: update t_user set tagId=? where userID=?
Hibernate:
update t_user set tagId=? where userID=?
Hibernate: update t_user set tagId=?
where userID=?
Rhythmk 学习 Hibernate 05 - Hibernate 表间关系 [ManyToOne,OneToMany],布布扣,bubuko.com
Rhythmk 学习 Hibernate 05 - Hibernate 表间关系 [ManyToOne,OneToMany]
标签：style blog class code java ext
原文地址：http://www.cnblogs.com/rhythmK/p/3704133.html
