hibernate多对多,转换为两个一对多
例如，现在有商品表，订单表，两者是多对多的关系，
--订单表
create table ORDERS
(
ID NUMBER(8) not null,
TOTAL NUMBER(8,2) not null,
CREATED_DATE VARCHAR2(40) not null,
REALNAME VARCHAR2(20),
TELPHONE VARCHAR2(20),
MOBILE NUMBER(20),
ADDRESS VARCHAR2(200) not null,
POSTCODE VARCHAR2(12),
STATE NUMBER(1),
ACCOUNT_ID VARCHAR2(40),
PAYMENT_ID NUMBER(4),
DELIVERY_ID NUMBER(4),
PAYMENT_STATE NUMBER(1),
MEMO VARCHAR2(400)
)
--商品表
create table PRODUCT
(
ID NUMBER(8) not null,
NAME VARCHAR2(200) not null,
CREATED_DATE VARCHAR2(40),
DESCRIPTION VARCHAR2(4000),
IMAGEURL VARCHAR2(200),
PRICE NUMBER(6,2) not null,
STOCK NUMBER(8),
STATE NUMBER(1) not null,
CATEGORY_ID NUMBER(4) not null,
DISCOUNT NUMBER(2)
)
--中间表
create table ORDERITEM
(
ORDER_ID NUMBER(8),
PRODUCT_ID NUMBER(8),
ORIGIN_PRICE NUMBER(6,2),
PRICE NUMBER(6,2),
QUANTITY NUMBER(6),
ID VARCHAR2(40) not null
)
传统的多对多映射会在order.hbm.xml中这样设置：
但是，此时中间表orderitem中多了三个字段,此时就不能用上面这种方法了，
那么就可以转化成两个一对多（或者说两个多对一）
步骤：
1.生成orderitem的POJO类，并改造成如下内容：
public class Orderitem implementsjava.io.Serializable {
// Fields
private String id;
private Double originPrice;
private Double price;
private Long quantity;
private Order order;
private Product product;
// Constructors
public Orderitem() {
}
// Property accessors
public String getId() {
return this.id;
}
public void setId(String id) {
this.id = id;
}
public Double getOriginPrice() {
return this.originPrice;
}
public void setOriginPrice(Double originPrice){
this.originPrice = originPrice;
}
public Double getPrice() {
return this.price;
}
public void setPrice(Double price) {
this.price = price;
}
public Long getQuantity() {
return this.quantity;
}
public void setQuantity(Long quantity) {
this.quantity = quantity;
}
public Order getOrder() {
return order;
}
public void setOrder(Order order) {
this.order = order;
}
public Product getProduct() {
return product;
}
public void setProduct(Product product) {
this.product = product;
}
2.配置映射文件
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">