一对多的单向关联

例子：一个Group对应多个User。预计的表结构就是：

　　Annotation 配置：

　　　　　　　Group:

package com.bjsxt.hibernate;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name="t_group")
public class Group {
    private Integer id;
    
    private String name;
    
    private Set<User> users = new HashSet<User>();

    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @OneToMany
    @JoinColumn(name="groupId")//字段别名
    public Set<User> getUsers() {
        return users;
    }

    public void setUsers(Set<User> users) {
        this.users = users;
    }
}

　　　　　　　　User:

package com.bjsxt.hibernate;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="t_user")
public class User {
    private Integer id;
    
    private String name;
    
    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

　　　　XML 配置：

　　　　　Group:　

package com.bjsxt.hibernate;

import java.util.HashSet;
import java.util.Set;

public class Group {
    private Integer id;
    
    private String name;
    
    private Set<User> users = new HashSet<User>();

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Set<User> getUsers() {
        return users;
    }

    public void setUsers(Set<User> users) {
        this.users = users;
    }
}

　　　　　Group.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="com.bjsxt.hibernate">
    <class name="Group" table="t_group">
        <id name="id" column="id">
            <generator class="native"/>
        </id>
        <property name="name" column="name" />
        <set name="users">
13             <key column="groupId"></key>
14             <one-to-many class="User"/>
15         </set>
    </class>
</hibernate-mapping>

　　　　　　User:

package com.bjsxt.hibernate;

public class User {
    private Integer id;
    
    private String name;
    
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

　　　　　　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="com.bjsxt.hibernate">
    <class name="User" table="t_user">
        <id name="id" column="id">
            <generator class="native"/>
        </id>
        <property name="name" column="name" />
    </class>
</hibernate-mapping>

生成的SQL语句：

jar包链接: https://pan.baidu.com/s/1jIsm7Ng 密码: ixpe

代码链接: https://pan.baidu.com/s/1o7GQC4q 密码: y7mb