框架漫谈之hibernate(四)hibernate一对多、多对多实体类xml配置

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1.数据库建表SQL

create database test_hibernate;use test_hibernate;/*创建客户表*/CREATE TABLE `cst_customer` (  `cust_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '客户编号(主键)',  `cust_name` varchar(32) NOT NULL COMMENT '客户名称(公司名称)',  `cust_source` varchar(32) DEFAULT NULL COMMENT '客户信息来源',  `cust_industry` varchar(32) DEFAULT NULL COMMENT '客户所属行业',  `cust_level` varchar(32) DEFAULT NULL COMMENT '客户级别',  `cust_address` varchar(128) DEFAULT NULL COMMENT '客户联系地址',  `cust_phone` varchar(64) DEFAULT NULL COMMENT '客户联系电话',  PRIMARY KEY (`cust_id`)) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;/*创建联系人表*/CREATE TABLE `cst_linkman` (  `lkm_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '联系人编号(主键)',  `lkm_name` varchar(16) DEFAULT NULL COMMENT '联系人姓名',  `lkm_gender` varchar(10) DEFAULT NULL COMMENT '联系人性别',  `lkm_phone` varchar(16) DEFAULT NULL COMMENT '联系人办公电话',  `lkm_mobile` varchar(16) DEFAULT NULL COMMENT '联系人手机',  `lkm_email` varchar(64) DEFAULT NULL COMMENT '联系人邮箱',  `lkm_position` varchar(16) DEFAULT NULL COMMENT '联系人职位',  `lkm_memo` varchar(512) DEFAULT NULL COMMENT '联系人备注',  PRIMARY KEY (`lkm_id`)) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;/*创建用户表*/CREATE TABLE `sys_user` (  `user_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '用户id',  `user_code` varchar(32) NOT NULL COMMENT '用户账号',  `user_name` varchar(64) NOT NULL COMMENT '用户名称',  `user_password` varchar(32) NOT NULL COMMENT '用户密码',  `user_state` char(1) NOT NULL COMMENT '1:正常,0:暂停',  PRIMARY KEY (`user_id`)) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;/*创建角色表*/create table `sys_role`(    role_id bigint(32) primary key auto_increment,    role_name varchar(100),    role_memo varchar(255));/*创建用户和角色关联系表*/CREATE TABLE `sys_user_role` (  `role_id` bigint(32) NOT NULL COMMENT '角色id',  `user_id` bigint(32) NOT NULL COMMENT '用户id',  PRIMARY KEY (`role_id`,`user_id`),  KEY `FK_user_role_user_id` (`user_id`),  CONSTRAINT `FK_user_role_role_id` FOREIGN KEY (`role_id`) REFERENCES `sys_role` (`role_id`) ON DELETE NO ACTION ON UPDATE NO ACTION,  CONSTRAINT `FK_user_role_user_id` FOREIGN KEY (`user_id`) REFERENCES `sys_user` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION)

学习hibernate中多表映射应该遵循步骤：
1、明确表之前确实是如你所想的关系
2、在数据库中是SQL语句建立他们的之间的关系
3、在实体类中描述出两个实体之间的关系
4、在映射配置文件中建立他们的关系映射

2.客户联系人一对多

/** * 客户的实体类 * @author ZhuPengWei */public class Customer implements Serializable {    private Long custId;    private String custName;    private String custSource;    private String custIndustry;    private String custLevel;    private String custAddress;    private String custPhone;       //一对多关系映射：一个客户可以包含多个联系人    private Set<LinkMan> linkmans = new HashSet<LinkMan>(0);    //提供对外访问的setter,getter    .......}

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="test.domain">    <class name="Customer" table="cst_customer">        <id name="custId" column="cust_id">            <generator class="native"></generator>        </id>        <property name="custName" column="cust_name"></property>        <property name="custIndustry" column="cust_industry"></property>        <property name="custSource" column="cust_source"></property>        <property name="custLevel" column="cust_level"></property>        <property name="custAddress" column="cust_address"></property>        <property name="custPhone" column="cust_phone"></property>        <!-- 一对多关系映射：            涉及的标签：                set：                  作用：用于映射set集合属性。                 属性：                   name：指定集合属性的名称                   table:指定集合元素所对应的表。在一对多时，table属性可以不写。                one-to-many:                  作用：指定当前映射文件所对应的实体和集合元素之间的关系是一对多。                 属性：                    class:指定集合元素所对应的实体类名称                key：                 作用：用于映射外键的。                 属性：                    column：指定外键字段名称。        -->        <set name="linkmans" table="cst_linkman" >            <key column="lkm_cust_id"/>            <one-to-many class="LinkMan"/>        </set>     </class></hibernate-mapping>

/** * 一个联系人的实体 * @author ZhuPengWei */public class LinkMan implements Serializable {    private Long lkmId;    private String lkmName;    private String lkmGender;    private String lkmPhone;    private String lkmMobile;    private String lkmEmail;    private String lkmPosition;    private String lkmMemo;    //多对一关系映射：多个联系人对应一个客户    private Customer customer;    //提供对外访问的setter,getter    .......}

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="test.domain">    <class name="LinkMan" table="cst_linkman">        <id name="lkmId" column="lkm_id">            <generator class="native"></generator>        </id>        <property name="lkmName" column="lkm_name"></property>        <property name="lkmGender" column="lkm_gender"></property>        <property name="lkmPhone" column="lkm_phone"></property>        <property name="lkmMobile" column="lkm_mobile"></property>        <property name="lkmEmail" column="lkm_email"></property>        <property name="lkmPosition" column="lkm_position"></property>        <property name="lkmMemo" column="lkm_memo"></property>        <!-- 多对一关系映射             涉及的标签：                many-to-one                    作用：用于映射多对一的关系                    属性：                        name：指的实体类中引用客户实体的属性名称                        column：指的是从表中外键字段的名称                        class：指定的是属性所对应的实体类        -->        <many-to-one name="customer" class="Customer" column="lkm_cust_id"></many-to-one>    </class></hibernate-mapping>

3.用户角色多对多

/** * 角色的实体类 * @author ZhuPengWei */public class SysRole implements Serializable {    private Long roleId;    private String roleName;    private String roleMemo;    //多对多关系映射：一个角色可以赋予多个用户    private Set<SysUser> users = new HashSet<SysUser>(0);    //对外提供setter,getter    .......}

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="test.domain">    <class name="SysRole" table="sys_role">        <id name="roleId" column="role_id">            <generator class="native"></generator>        </id>        <property name="roleName" column="role_name"></property>        <property name="roleMemo" column="role_memo"></property>        <!-- 多对多关系映射 -->        <set name="users" table="user_role_ref"  >            <key column="role_id"/>            <many-to-many class="SysUser" column="user_id"/>        </set>    </class></hibernate-mapping>

/** * 一个用户实体 * @author ZhuPengWei */public class SysUser implements Serializable {    private Long userId;    private String userCode;    private String userName;    private String userPassword;    private String userState;    //多对多关系映射：一个用户可以有多个角色    private Set<SysRole> roles = new HashSet<SysRole>(0);    //对外提供setter,getter    .......}

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="test.domain">    <class name="SysUser" table="sys_user">        <id name="userId" column="user_id">            <generator class="native"></generator>        </id>        <property name="userCode" column="user_code"></property>        <property name="userName" column="user_name"></property>        <property name="userPassword" column="user_password"></property>        <property name="userState" column="user_state"></property>        <!-- 多对多的关系映射   -->        <set name="roles" table="user_role_ref" >            <key column="user_id"/>            <many-to-many class="SysRole" column="role_id"/>        </set>    </class></hibernate-mapping>

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