OneToOne annotation 双向关联
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package com.hibernate.entity;import java.io.Serializable;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.OneToOne;@Entitypublic class Husband implements Serializable {/** * */private static final long serialVersionUID = 2476364405175138004L;private int id;private String name;private Wife wife;@Id@GeneratedValuepublic int getId() {return id;}public String getName() {return name;}@OneToOnepublic Wife getWife() {return wife;}public void setId(int id) {this.id = id;}public void setName(String name) {this.name = name;}public void setWife(Wife wife) {this.wife = wife;}}?
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package com.hibernate.entity;import java.io.Serializable;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.OneToOne;@Entitypublic class Wife implements Serializable {/** * */private static final long serialVersionUID = 5270130768836331730L;private int id;private String name;private Husband husband;@Id@GeneratedValuepublic 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;}@OneToOne(mappedBy="wife")public Husband getHusband() {return husband;}public void setHusband(Husband husband) {this.husband = husband;}}??
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注意：Wife类的getHusband()上用了mappedBy"wife"
这个意思是说，我这里的OneToOne就不用管了，只用Husband里的getWife()上的OneToOne关系
生成的表为Husband参考Wife，有了wifeid，才能有Husband
Husband为这个关系的拥有者
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如果Wife类的getHusband()只有@OneToOne，没有mappedBy，那么生成的两张表都会有对方的外键，造成外键冗余。
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