Hibernate中表与表的关系模板代码
一对多的关系
<!-- users属性 与User的一对多 -->
<set name="users">
<key column="departmentId"></key>
<one-to-many class="User" />
</set>
一对多
多对一关系
<!-- department 用户与部门的多对一 -->
<many-to-one name="department" class="Department" column="departmentId">
</many-to-one>
多对一
多对多关系
<!-- users属性，本类与User的多对多 -->
<set name="users" table="itcast_user_role">
<key column="roleId"></key>
<many-to-many class="User" column="userId"></many-to-many>
</set>
<!-- roles属性，本类与Role的多对多 -->
<set name="roles" table="itcast_user_role">
<key column="userId"></key>
<many-to-many class="Role" column="roleId"></many-to-many>
</set>
需要第三表来维护
模板实例
实体类
Department.java
package cn.zzuli.oa.domain;
import java.util.HashSet;
import java.util.Set;
/**
* 部门
* @author LZH
* @date 2017年2月23日
*/
public class Department {
private Long id;
private Set<User> users = new HashSet<User>();
private Department parent;
private Set<Department> children = new HashSet<Department>();
private String name;
private String description;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Set<User> getUsers() {
return users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
public Department getParent() {
return parent;
}
public void setParent(Department parent) {
this.parent = parent;
}
public Set<Department> getChildren() {
return children;
}
public void setChildren(Set<Department> children) {
this.children = children;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
Role.java
package cn.zzuli.oa.domain;
import java.util.HashSet;
import java.util.Set;
/**
* 岗位
* @author LZH
* @date 2017年2月23日
*/
public class Role {
private Long id;
private String name;
private String description;
private Set<User> users = new HashSet<User>();
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Set<User> getUsers() {
return users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
}
User.java
package cn.zzuli.oa.domain;
import java.util.HashSet;
import java.util.Set;
/**
* 用户
* @author LZH
* @date 2017年2月23日
*/
public class User {
private Long id;
private Department department;
private Set<Role> roles = new HashSet<Role>();
private String loginName; // 登录名
private String password; // 密码
private String name; // 真实姓名
private String gender; // 性别
private String phoneNumber; // 电话号码
private String email; // 电子邮件
private String description; // 说明
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Department getDepartment() {
return department;
}
public void setDepartment(Department department) {
this.department = department;
}
public Set<Role> getRoles() {
return roles;
}
public void setRoles(Set<Role> roles) {
this.roles = roles;
}
public String getLoginName() {
return loginName;
}
public void setLoginName(String loginName) {
this.loginName = loginName;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getPhoneNumber() {
return phoneNumber;
}
public void setPhoneNumber(String phoneNumber) {
this.phoneNumber = phoneNumber;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
对应配置文件
Department.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 package="cn.zzuli.oa.domain">
<class name="Department" table="department">
<id name="id" column="id">
<generator class="native"></generator>
</id>
<property name="name" column="name"></property>
<property name="description" column="description"></property>
<!-- users属性 与User的一对多 -->
<set name="users">
<key column="departmentId"></key>
<one-to-many class="User" />
</set>
<!-- parent属性 与Department多对一 -->
<many-to-one name="parent" class="Department" column="parentId">
</many-to-one>
<!-- children 与Department一对多 -->
<set name="children">
<key column="parentId"></key>
<one-to-many class="Department" />
</set>
</class>
</hibernate-mapping>
Role.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="cn.itcast.oa.domain">
<class name="Role" table="itcast_role">
<id name="id">
<generator class="native"/>
</id>
<property name="name"/>
<property name="description"/>
<!-- users属性，本类与User的多对多 -->
<set name="users" table="user_role">
<key column="roleId"></key>
<many-to-many class="User" column="userId"></many-to-many>
</set>
</class>
</hibernate-mapping>
User.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="cn.itcast.oa.domain">
<class name="User" table="itcast_user">
<id name="id">
<generator class="native"/>
</id>
<property name="loginName"/>
<property name="password"/>
<property name="name"/>
<property name="gender" />
<property name="phoneNumber"/>
<property name="email"/>
<property name="description"/>
<!-- department属性，本类与Department的多对一 -->
<many-to-one name="department" class="Department" column="departmentId"></many-to-one>
<!-- roles属性，本类与Role的多对多 -->
<set name="roles" table="user_role">
<key column="userId"></key>
<many-to-many class="Role" column="roleId"></many-to-many>
</set>
</class>
</hibernate-mapping>
数据表模型
数据表模型
总结：
图片总结
1、写注释
格式为：？属性，表达的是本对象与？的？关系。
例：“department属性，本对象与Department的多对一”
2、模版
多对一
<many-to-one name="" class="" column=""/>
一对多
<set name="">
<key column=""></key>
<one-to-many class=""/>
</set>
多对多
<set name="" table="">
<key column=""></key>
<many-to-many class="" column=""/>
</set>
3、填空
•name属性：属性名（注释中的第1问号）
•class属性：关联的实体类型（注释中的第2个问号）
•column属性：
•<many-to-onecolumn="..">：一般可以写成属性名加Id后缀，如属性为department，则column值写成departmentId。
•一对多中的<keycolumn="..">：从关联的对方（对方是多对一）映射中把column值拷贝过来。
•多对多中的<keycolumn=“..”>：一般可以写成本对象的名加Id后缀，如本对象名为User，则写为userId。
•多对多中的<many-to-manycolumn=“..”>：一般可以写为关联对象的名称加Id后缀。
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