hibernate表关联的各种配置：
1、多对多单向：
user----->role
user.hbm.xml:
role.hbm.xml:
2、多对多双向：
user.hbm.xml:
role.hbm.xml:
3、一对多单向：
student（多）----->classes(一)
student.hbm.xml:
classes.hbm.xml:
//classesid是在student表中加的一字段列名
4、一对多双向：
student（多）----->classes(一)
student.hbm.xml:
classes.hbm.xml:
//inverse表示维护关系反转，true表示失效，不由classes
//这端来维护。cascade表示级联，即当对classes操作时，发现还未有student持久化，会自动持久化student的
5、一对一主键关联（单向关联Person---->IdCard）
一对一主键关联映射:让两个实体对象的id保持相同，这样可以避免多余的字段被创建
Person.Java
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package com.bjsxt.hibernate;
public class Person {
private int id;
private String name;
private IdCard idCard;
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;
}
public IdCard getIdCard() {
return idCard;
}
public void setIdCard(IdCard idCard) {
this.idCard = idCard;
}
}
package com.bjsxt.hibernate;
public class Person {
private int id;
private String name;
private IdCard idCard;
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;
}
public IdCard getIdCard() {
return idCard;
}
public void setIdCard(IdCard idCard) {
this.idCard = idCard;
}
}
Person.hbm.xml://其对应的表中只有id,name两个属性
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
//主键生成方式受制于IdCard主键生成方式
idCard
IdCard.java:
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package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
}
package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
}
IdCard.hbm.xml:
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
6、一对一主键关联（双向Person<-------->IdCard）
与一对一主键关联(单向)大体一致，只不过IdCard.hbm.xml的配置里要一个one-to-ont属性，IdCard.java里加一个Person的引用。
IdCard.java:
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package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
private Person person;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
}
package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
private Person person;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
}
IdCard.hbm.xml:
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"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
7、一对一唯一外键关联（单向Person----->IdCard）
其实是多对对一的一个特例。
Person.java
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package com.bjsxt.hibernate;
public class Person {
private int id;
private String name;
private IdCard idCard;
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;
}
public IdCard getIdCard() {
return idCard;
}
public void setIdCard(IdCard idCard) {
this.idCard = idCard;
}
}
package com.bjsxt.hibernate;
public class Person {
private int id;
private String name;
private IdCard idCard;
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;
}
public IdCard getIdCard() {
return idCard;
}
public void setIdCard(IdCard idCard) {
this.idCard = idCard;
}
}
Person.hbm.xml
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"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
IdCard.java
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package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
}
package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
}
IdCard.hbm.xml
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"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
8、一对一唯一外键关联（双向Person<----->IdCard)
相对于上面的一对一唯一外键关联（单向）不同的是，IdCard.java添加了Person的引用与IdCard.hbm.xml添加了one-to-one标签。
IdCard.java:
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package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
private Person person;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
}
package com.bjsxt.hibernate;
public class IdCard {
private int id;
private String cardNo;
private Person person;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCardNo() {
return cardNo;
}
public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
}
IdCard.hbm.xml:
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"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
