我在我的数据库结构如下:休眠,试图访问孙子字段一对多的关系
我已经映射他们在Hibernate的配置文件是这样的:
<hibernate-mapping>
<class name="model.CartEntity" table="cart">
<id name="id" type="int" column="id">
<generator class="native" />
</id>
<set name="products" table="cart_product_record"
inverse="true" lazy="false" fetch="select" cascade="save-update, delete">
<key>
<column name="cart_id" not-null="false" />
</key>
<one-to-many class="model.ProductRecordEntity" />
</set>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="model.ProductRecordEntity" table="product_record">
<id name="id" type="int" column="id">
<generator class="native"/>
</id>
<many-to-one name="product" class="model.ProductEntity" fetch="select" cascade="save-update, delete">
<column name="product_id" />
</many-to-one>
<many-to-one name="cart" class="model.CartEntity" fetch="select" cascade="save-update, delete">
<column name="cart_id" not-null="true" />
</many-to-one>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="model.ProductEntity" table="product">
<id name="id" type="int" column="id">
<generator class="native" />
</id>
<set name="productRecords" table="product_record_product" inverse="true"
lazy="false" fetch="select" cascade="save-update, delete">
<key>
<column name="product_id" not-null="true" />
</key>
<one-to-many class="model.ProductRecordEntity" />
</set>
</class>
</hibernate-mapping>
我从数据库中检索具有所有产品记录的购物车,迄今为止没有问题,我正确地获取了所有必要的数据。
CartEntity cart = findById(id);
List<ProductRecordEntity> productRecords = cart.getProductRecords();
问题是,当我尝试从产品记录得到的产品:
for (ProductRecordEntity productRecord: productRecords){
ProductEntity product = productRecord.getProduct();
}
我得到一个对象与它们的默认值,而不是从数据库中的信息的所有字段。
将实体保存到数据库中时,ID将正确填充。
产品记录表:
和产品表:
这些都是实体:
public class CartEntity {
private int id;
private Set<ProductRecordEntity> products = new HashSet<ProductRecordEntity>();
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public Set<ProductRecordEntity> getProducts() {
return products;
}
public void setProducts(Set<ProductRecordEntity> products) {
this.products = products;
}
}
public class ProductRecordEntity {
private int id;
private CartEntity cart;
private ProductEntity product;
public CartEntity getCart() {
return cart;
}
public void setCart(CartEntity cart) {
this.cart = cart;
}
public ProductEntity getProduct() {
return product;
}
public void setProduct(ProductEntity product) {
this.product = product;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
public class ProductEntity implements Serializable{
private int id;
private Set<ProductRecordEntity> productRecords;
public Set<ProductRecordEntity> getProductRecords() {
return productRecords;
}
public void setProductRecords(Set<ProductRecordEntity> productRecords) {
this.productRecords = productRecords;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
这是操作上的顺序数据库:
persist(cartEntity);
persist(productEntity);
productRecordEntity.setCartEntity(cartEntity);
cartEntity.getProducts().add(productRecordEntity);
productRecordEntity.setProduct(productEntity);
persist(productRecordEntity);
productEntity.getProductRecords().add(productRecordEntity);
update(productEntity);
update(cartEntity);
任何想法我失踪了?我找不到问题出在哪里,我翻了两倍,三重检查了一切。
能否请您发表您的产品模型类和DAO? –