hibernate one2many

package com.bjsxt.hibernate;

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

import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinColumns;
import javax.persistence.OneToMany;
import javax.persistence.OneToOne;
import javax.persistence.PrimaryKeyJoinColumn;
import javax.persistence.Table;

@Entity
@Table(name="t_group")
public class Group {
@Id
@GeneratedValue                                 //这个  @Id 和  one2many  要么都加在getter上  要么 都加在 变量上
private int id;

private String name;


@OneToMany
@JoinColumn(name="groupId")                                // 一直以为 哪边加joinColumn 哪边加字段     经过这次试验  发现   字段只会加在多对一  一对多   多的一方；
private Set<User> users = new HashSet<User>();

 

public int getId() {
return id;
}

public Set<User> getUsers() {
return users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
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package com.bjsxt.hibernate;

import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinColumns;
import javax.persistence.ManyToOne;
import javax.persistence.OneToOne;
import javax.persistence.PrimaryKeyJoinColumn;
import javax.persistence.Table;

@Entity
@Table(name="t_user")
public class User {
@Id
@GeneratedValue
private int id;
private String name;

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}



}

}