我有一个列表的NHibernate问题,它被映射为抽象类的子类。
首先是抽象类的映射:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
auto-import="false"
assembly="Magma.Core"
namespace="Magma.Core.Business">
<class name="SyndicatePart" table="biz_syndicatepart" abstract="true" lazy="false">
<id name="Id" column="id">
<generator class="guid.comb" />
</id>
<discriminator column="parttype" not-null="true" />
<property name="Identifier" column="name" not-null="true" />
<property name="Share" column="share" not-null="true" />
<property name="CadasterNumber" column="cadaster_number" not-null="true" />
<many-to-one name="Account" column="accountid" lazy="proxy" cascade="all" />
<many-to-one name="Syndicate" column="syndicateid" lazy="proxy" cascade="all" />
<subclass name="Condo" discriminator-value="condo" lazy="false">
<property name="OwnerType" column="ownertype" />
<many-to-one name="Building" column="buildingid" />
<many-to-one name="Address" column="addressid" />
<bag name="Tenants" access="field.camelcase-underscore" table="biz_tenant" inverse="true" cascade="all-delete-orphan">
<key column="syndicatepartid" />
<one-to-many class="Tenant" />
</bag>
</subclass>
<subclass name="Parking" discriminator-value="park" lazy="false" />
<subclass name="Locker" discriminator-value="lock" lazy="false" />
</class>
</hibernate-mapping>
注意子类“公寓”,“停车”和“储物柜”(在我的情况下,只有公寓有其他属性)。这是使用这些子类的列表对象的映射:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="Magma.Core"
namespace="Magma.Core.Business">
<class name="Syndicate" table="biz_syndicate" abstract="true" lazy="false">
<id name="Id" column="id">
<generator class="guid.comb" />
</id>
<discriminator column="orientation" not-null="true" />
<property name="Name" column="name" not-null="true" />
<many-to-one name="Manager" column="managerid" cascade="all-delete-orphan" />
<bag name="Buildings" table="biz_building" inverse="true" cascade="all-delete-orphan">
<key column="syndicateid" />
<one-to-many class="Building" />
</bag>
<bag name="Parkings" table="biz_syndicatepart" inverse="true" cascade="all-delete-orphan">
<key column="syndicateid" />
<one-to-many class="Parking" />
</bag>
<bag name="Lockers" table="biz_syndicatepart" inverse="true" cascade="all-delete-orphan">
<key column="syndicateid" />
<one-to-many class="Locker" />
</bag>
<subclass name="VerticalSyndicate" discriminator-value="vertical" lazy="false" />
<subclass name="HorizontalSyndicate" discriminator-value="horizontal" lazy="false" />
</class>
</hibernate-mapping>
每个列表都被映射为一个指向同一个表但不同类别的包,具体取决于列表(公寓,停车场和储物柜)。
现在问题。问题是,当我尝试访问任何这些列表时,NHibernate会获取biz_syndicatepart
表中所有行的所有,并根据列表将其强制转换为正确的类。所以假设我在表格中有3行,如果我访问Parkings
列表,我将有3个停车位。如果我访问Lockers
列表,我将有3个储物柜!这是为停车列表生成的SQL:
SELECT parkings0_.syndicateid as syndicat7_1_,
parkings0_.id as id1_,
parkings0_.id as id39_0_,
parkings0_.name as name39_0_,
parkings0_.share as share39_0_,
parkings0_.cadaster_number as cadaster5_39_0_,
parkings0_.accountid as accountid39_0_,
parkings0_.syndicateid as syndicat7_39_0_
FROM biz_syndicatepart parkings0_
WHERE parkings0_.syndicateid = '2310fcdf-8ab3-48dd-9a75-9f1e00f6f4fd' /* @p0 */
首先,请注意双parkings0_.id
。这是正常的吗? parkings0_.syndicateid
(select语句的第一行和最后一行)也是如此。这个我真的不明白。
另请注意,插入 no 判别WHERE
子句以指定我想要的列表类型。我假设如果我访问Parkings
列表,我会看到WHERE [discriminator-column] = [discriminator-value]
,在我的情况下WHERE parttype = 'park'
,但它不在语句中,所以这就是每行返回的原因。
我读到这可能是NHibernate中的一个错误(我目前正在使用版本3.1 GA)但是阅读错误的描述似乎当使用表时列表的键位于子类表中时会发生错误每个子类策略(加入子类)所以我认为它不适用于我的情况。
有人可以帮我这个吗?!我的映射文件有问题吗?为什么SELECT中的_id
加倍,为什么没有鉴别器WHERE
子句?
答案 0 :(得分:2)
简单的解决方法是在集合映射中添加where子句。例如。
<bag name="Parkings" table="biz_syndicatepart" inverse="true" cascade="all-delete-orphan" where="parttype='park'">
<key column="syndicateid" />
<one-to-many class="Parking" />
</bag>