我正在尝试将表从多对一映射转换为具有中间映射表的多对多。但是,当我切换它并尝试用NHibernate对它进行查询时,它给出了这个错误:"Interceptor.OnPrepareStatement(SqlString) returned null or empty SqlString“。
我的查询最初是更复杂的查询,但我将其切换为基本的fetch all,并且仍然存在问题:
Session.QueryOver<T>().Future();这似乎要么是我的模型映射文件中的问题,要么是我的数据库中的什么问题。
以下是我的模型映射:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="GBI.Core" namespace="GBI.Core.Models">
<class name="Market" table="gbi_Market">
<id name="Id" column="MarketId">
<generator class="identity" />
</id>
<property name="Name" />
<property name="Url" />
<property name="Description" type="StringClob" />
<property name="Rating" />
<property name="RatingComment" />
<property name="RatingCommentedOn" />
<many-to-one name="RatingCommentedBy" column="RatingCommentedBy" lazy="proxy"></many-to-one>
<property name="ImageFilename" />
<property name="CreatedOn" />
<property name="ModifiedOn" />
<property name="IsDeleted" />
<many-to-one name="CreatedBy" column="CreatedBy" lazy="proxy"></many-to-one>
<many-to-one name="ModifiedBy" column="ModifiedBy" lazy="proxy"></many-to-one>
<set name="Content" where="IsDeleted=0 and ParentContentId is NULL" order-by="Ordering asc, CreatedOn asc, Name asc" lazy="extra">
<key column="MarketId" />
<one-to-many class="MarketContent" />
</set>
<set name="FastFacts" where="IsDeleted=0" order-by="Ordering asc, CreatedOn asc, Name asc" lazy="extra">
<key column="MarketId" />
<one-to-many class="MarketFastFact" />
</set>
<set name="NewsItems" table="gbi_NewsItem_Market_Map" lazy="true">
<key column="MarketId" />
<many-to-many class="NewsItem" fetch="join" column="NewsItemId" where="IsDeleted=0"/>
</set>
<!--<set name="MarketUpdates" table="gbi_Market_MarketUpdate_Map" lazy="extra">
<key column="MarketId" />
<many-to-many class="MarketUpdate" fetch="join" column="MarketUpdateId" where="IsDeleted=0" order-by="CreatedOn desc" />
</set>-->
<set name="Documents" table="gbi_Market_Document_Map" lazy="true">
<key column="MarketId" />
<many-to-many class="Document" fetch="join" column="DocumentId" where="IsDeleted=0"/>
</set>
</class>
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="GBI.Core" namespace="GBI.Core.Models">
<class name="MarketUpdate" table="gbi_MarketUpdate">
<id name="Id" column="MarketUpdateId">
<generator class="identity" />
</id>
<property name="Description" />
<property name="CreatedOn" />
<property name="ModifiedOn" />
<property name="IsDeleted" />
<!--<many-to-one name="Market" column="MarketId" lazy="proxy"></many-to-one>-->
<set name="Comments" where="IsDeleted=0" order-by="CreatedOn desc" lazy="extra">
<key column="MarketUpdateId" />
<one-to-many class="MarketUpdateComment" />
</set>
<many-to-one name="CreatedBy" column="CreatedBy" lazy="proxy"></many-to-one>
<many-to-one name="ModifiedBy" column="ModifiedBy" lazy="proxy"></many-to-one>
</class>
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="GBI.Core" namespace="GBI.Core.Models">
<class name="MarketUpdateMarketMap" table="gbi_Market_MarketUpdate_Map">
<id name="Id" column="MarketUpdateMarketMapId">
<generator class="identity" />
</id>
<property name="CreatedOn" />
<property name="ModifiedOn" />
<property name="IsDeleted" />
<many-to-one name="CreatedBy" column="CreatedBy" lazy="proxy"></many-to-one>
<many-to-one name="ModifiedBy" column="ModifiedBy" lazy="proxy"></many-to-one>
<many-to-one name="MarketUpdate" column="MarketUpdateId" lazy="proxy"></many-to-one>
<many-to-one name="Market" column="MarketId" lazy="proxy"></many-to-one>
</class>
正如我提到的,MarketUpdate最初与市场是多对一的(MarketId专栏仍然在那里,但我忽略了它。这会是一个问题吗?)。但我已经在Market_MarketUpdate_Map表中添加了,以使其成为多对多。
我在绕圈子想弄清楚这可能是什么。在搜索时,我找不到任何关于此错误的引用。而且它没有提供太多细节。
使用:
NHibernate 2.2
.NET 4.0
SQL Server 2005
发布于 2010-12-23 05:54:23
问题在于,在visual studio中,xml映射文件被设置为内容,而不是嵌入的资源。改变它解决了我所有的问题。
发布于 2014-01-14 23:17:33
如果您使用Fluent而不是xml进行映射,并遇到此问题,请尝试删除%root%\LocalCache\NHibernate中生成的xml文件。
https://stackoverflow.com/questions/4512252
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