在链接表中使用额外的文件（在xml文件中映射），我有很多关系 . 使用标准api如何为产品名称添加限制？
public class Recipe implements Serializable{
private int id_re;
private String name;
private Set<ProductRecipe> listOfRecipe_Product = new HashSet<>(0);
}
public class ProductRecipe implements Serializable{
private ProductRecipeMapping id;
private float quantity;
}
public class ProductRecipeMapping implements Serializable{
private Product product;
private Recipe recipe;
}
public class Product implements Serializable{
private int id_p;
private String name;
}
制图：
<class entity-name="recipe" name="Recipe" table="recipe">
<id name="id_re" type="java.lang.Integer">
<column name="id_re" />
<generator class="identity" />
</id>
<set name="listOfRecipe_Product" table="recipe_product" lazy="false" fetch="select" cascade="all">
<key>
<column name="id_re" not-null="true" />
</key>
<one-to-many entity-name="productRecipe" />
</set>
</class>
<class entity-name="productRecipe" name="ProductRecipe" table="recipe_product">
<composite-id name="id" class="ProductRecipeMapping" >
<key-many-to-one name="recipe" entity-name="recipe" column="id_re" />
<key-many-to-one name="product" entity-name="product" column="id_p" />
</composite-id>
<property name="quantity" type="float" column="quantity" />
</class>
<class entity-name="product" name="Product" table="product">
<id name="id_p" type="java.lang.Integer" column="id_p">
<generator class="identity" />
</id>
<property name="name" column="name" type="java.lang.String" not-null="true" length="255"/>
</class>
例如 . 我使用标准获取配方名称测试：
Criteria cr = session.createCriteria(Recipe.class);
cr.add(Restrictions.eq("name", "test"));
但我不知道所有食谱的列表名称都是cr.add（Restrictions.eq（“product.name”，“test”））; （但没有工作）
我使用2个想法来解决这个问题，但没有任何效果：
1） Restrictions.eq("listOfRecipe_Product.id.product.name", "test") 但我收到错误 org.hibernate.QueryException: could not resolve property: listOfRecipe_Product.id.product.name of: recipe
2）
cr.createCriteria("listOfRecipe_Product")
.createCriteria("id")
.createCriteria("product")
.add(Restrictions.eq("name", "test"));
我收到错误 org.hibernate.QueryException: Criteria objects cannot be created directly on components. Create a criteria on owning entity and use a dotted property to access component property: listOfRecipe_Product.id
1 回答
您需要创建别名才能向映射实体添加约束;
例如 . ：