NHibernate的 - 如何映射到一个没有表(自定义的SQL查询)类 [英] NHibernate - How to map to a class that has no table (for custom sql queries)
问题描述
更新 - 编辑过的配置以增强可读性 在SO
您好,
我一直在学习NHibernate的一两天,但被陷在一个点上。
我需要能够执行自定义存储过程和使用的NHibernate将它们回映射到域类。
我有这个工作,其中的自定义查询映射回映射到数据库表,如图许多NHibernate的例子对象的情景(见下文第一部分)。
不过在配置为下面的第二部分,查询拉从目标表中只有2列。出于这个原因,我创建了一个自定义的对象,这样的NHibernate有事返回值映射到。自定义对象的属性具有相同的名称从自定义过程的返回列。
当我运行我的测试中,我得到这样一个例外:
NHibernate.MappingException:无 持留为: Proj.DataEntityTracker.Domain.Entities.CustomObject
所以我想在SQL查询部分的映射是不够的NHibernate的返回值映射到对象的属性。
所以我的问题是 - 我怎么设置对此有没有相应的数据库表中,这样我可以在存储过程的结果映射到对象的映射
?< XML版本=" 1.0"编码=" UTF-8英寸?> <休眠映射的xmlns ="金塔:NHibernate的映射 - 2.2" 装配=" Proj.DataEntityTracker.Domain" 命名空间=" Proj.DataEntityTracker.Domain.Entities"> <类名=" TrackedEntityProperty"表=" TrackedEntityProperties"> < ID名称=" ID"类型="的Int32"未保存价值=" 0"> <生成器类="天然">< /发电机> < / ID> <属性名=" TrackedEntityID" /> <属性名="名称" /> <属性名=" CreatedDate" /> <属性名=" ChangedDate" /> <属性名="数据类型" /> <属性名=" CurrentValue的" /> <属性名=" RequestPropertyValueQuestion" /> <属性名=" NullResponseIsAcceptable" /> <属性名="复制" /> <属性名="频率" /> <属性名=" IsActive" /> <属性名="&请将isDeleted QUOT; /> <属性名=" LastUpdateTaskGenerated" /> <属性名=" LastUpdateTaskCompleted" /> <属性名=" LastUpdateTaskCancelled" /> < /类> < SQL查询的名称=" usp_GetTrackedEntityPropertiesDueForUpdate" > <返回别名=" usp_GetTrackedEntityPropertiesDueForUpdate"类=" TrackedEntityProperty"> <返回,属性名=" ID"列=" ID" /> <返回,属性名=" TrackedEntityID"列=" TrackedEntityID" /> <返回,属性名="名称"列="名称" /> <返回,属性名=" CreatedDate"列=" CreatedDate" /> <返回,属性名=" ChangedDate"列=" ChangedDate" /> <返回,属性名="数据类型"列="数据类型" /> <返回,属性名=" CurrentValue的"列=" CurrentValue的" /> <返回,属性名=" RequestPropertyValueQuestion"列=" RequestPropertyValueQuestion" /> <返回,属性名=" NullResponseIsAcceptable"列=" NullResponseIsAcceptable" /> <返回,属性名="复制"列="复制" /> <返回,属性名="频率"列="频率" /> <返回,属性名=" IsActive"列=" IsActive" /> <返回,属性名="&请将isDeleted QUOT;列="&请将isDeleted QUOT; /> <返回,属性名=" LastUpdateTaskGenerated"列=" LastUpdateTaskGenerated" /> <返回,属性名=" LastUpdateTaskCompleted"列=" LastUpdateTaskCompleted" /> <返回,属性名=" LastUpdateTaskCancelled"列=" LastUpdateTaskCancelled" /> < /回报> EXEC usp_GetTrackedEntityPropertiesDueForUpdate:TrackedEntityID < / SQL查询> < SQL查询的名称=" usp_SomeCustomSproc"> <返回别名=" usp_SomeCustomSproc"类=" CustomObject"> <返回,属性名=" ID"列=" ID" /> <返回,属性名="名称"列="名称" /> < /回报> EXEC usp_SomeCustomSproc:TrackedEntityID < / SQL查询> < /休眠映射>
你要找的是什么预测。首先你需要修改你的查询
< SQL查询的名称=usp_SomeCustomSproc>
<返回标量列=ID类型=的Int32/>
<返回标量列=名称TYPE =字符串/>
EXEC usp_SomeCustomSproc:TrackedEntityID
< / SQL查询>
然后在code,你把它指定一个结果变压器。该AliasToBeanTransformer将列别名,并将它们映射到对象的属性。
session.GetNamedQuery(usp_SomeCustomSproc)
.SetInt32(TrackedEntityID,15)
.SetResultTransformer(Transformers.AliasToBean&其中; CustomObject>())
.LIST< CustomObject>()
Update - Edited config for readability in SO
Hi,
I've been learning NHibernate for a day or two but getting stuck on one point.
I need to be able to execute custom stored procedures and use NHibernate to map them back to domain classes.
I have this working for the scenario where the custom query maps back to a object that maps to a database table, as shown by many a nhibernate example (See first section below).
However in the config for the second section below, the query pulls only 2 columns from the target table. For this reason, I have created a custom object so that NHibernate has something to map the return values to. The custom object properties have the same name as the return columns from the custom procedure.
When I run my tests I get an exception like:
NHibernate.MappingException: No persister for: Proj.DataEntityTracker.Domain.Entities.CustomObject
So I guess the mapping under sql-query section is not enough for NHibernate to map the return values to the object properties.
So my question is - how do I set up a mapping for which there is no equivalent table in the database such that I can map the results of a stored procedure to that object?
<?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Proj.DataEntityTracker.Domain" namespace="Proj.DataEntityTracker.Domain.Entities"> <class name="TrackedEntityProperty" table="TrackedEntityProperties"> <id name="ID" type="Int32" unsaved-value="0"> <generator class="native"></generator> </id> <property name="TrackedEntityID" /> <property name="Name" /> <property name="CreatedDate" /> <property name="ChangedDate" /> <property name="DataType" /> <property name="CurrentValue" /> <property name="RequestPropertyValueQuestion" /> <property name="NullResponseIsAcceptable" /> <property name="Duplication" /> <property name="Frequency" /> <property name="IsActive" /> <property name="IsDeleted" /> <property name="LastUpdateTaskGenerated" /> <property name="LastUpdateTaskCompleted" /> <property name="LastUpdateTaskCancelled" /> </class> <sql-query name="usp_GetTrackedEntityPropertiesDueForUpdate" > <return alias="usp_GetTrackedEntityPropertiesDueForUpdate" class="TrackedEntityProperty"> <return-property name="ID" column="ID" /> <return-property name="TrackedEntityID" column="TrackedEntityID" /> <return-property name="Name" column="Name" /> <return-property name="CreatedDate" column="CreatedDate" /> <return-property name="ChangedDate" column="ChangedDate" /> <return-property name="DataType" column="DataType" /> <return-property name="CurrentValue" column="CurrentValue" /> <return-property name="RequestPropertyValueQuestion" column="RequestPropertyValueQuestion" /> <return-property name="NullResponseIsAcceptable" column="NullResponseIsAcceptable" /> <return-property name="Duplication" column="Duplication" /> <return-property name="Frequency" column="Frequency" /> <return-property name="IsActive" column="IsActive" /> <return-property name="IsDeleted" column="IsDeleted" /> <return-property name="LastUpdateTaskGenerated" column="LastUpdateTaskGenerated" /> <return-property name="LastUpdateTaskCompleted" column="LastUpdateTaskCompleted" /> <return-property name="LastUpdateTaskCancelled" column="LastUpdateTaskCancelled" /> </return> exec usp_GetTrackedEntityPropertiesDueForUpdate :TrackedEntityID </sql-query> <sql-query name="usp_SomeCustomSproc"> <return alias="usp_SomeCustomSproc" class="CustomObject"> <return-property name="ID" column="ID" /> <return-property name="Name" column="Name" /> </return> exec usp_SomeCustomSproc :TrackedEntityID </sql-query> </hibernate-mapping>
What you're looking for are projections. First of all you need to modify your query
<sql-query name="usp_SomeCustomSproc">
<return-scalar column="Id" type="Int32"/>
<return-scalar column="Name" type="String"/>
exec usp_SomeCustomSproc :TrackedEntityID
</sql-query>
Then in the code where you call it you specify a result transformer. The AliasToBeanTransformer will take column aliases and map them to properties on the object.
session.GetNamedQuery("usp_SomeCustomSproc")
.SetInt32("TrackedEntityID", 15)
.SetResultTransformer(Transformers.AliasToBean<CustomObject>())
.List<CustomObject>()
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