JDO查询帮助（按配料查找食谱）

@PersistenceCapable
class Recipe{

    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Long key;

    ...

    @Persistent(mappedBy = \"recipe\")
    private List<RecipeIngredient> ingredients
}

@PersistenceCapable(identityType = IdentityType.APPLICATION, detachable=\"true\")
class RecipeIngredient implements Serializable {

    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Key key;

    @Persistent
    Integer amount

    @Persistent
    Key unit

    @Persistent
    Key ingredient

    @Persistent
    Recipe recipe

@PersistenceCapable(identityType = IdentityType.APPLICATION, detachable=\"true\")
class Ingredient implements Serializable {

    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Key key;

    @Persistent
    String name