2010-02-12 138 views
3

我有這些遺留表,我通過nhibernate訪問,基本的一個實體訪問是好的,但我真的需要得到連接工作。nhibernate映射,加入沒有主鍵和外鍵

理想情況下,我會有主鍵和外鍵來定義連接,但因爲這些是遺留表,我只有合併id是表的索引,這些索引已用於性能的原因,所以我不能改變。

反正我有JobHeader表和屬性表

JobHeader映射看起來像這樣的時刻:


<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> 
    <class name="JobHeader " dynamic-update="true" table="JOB_HEADER"> 
    <composite-id> 
     <key-property name="Company" column="JBH_COMPANY" type="String(6)" /> 
     <key-property name="ContractRef" column="JBH_CONTRACT_REF" type="String(10)" /> 
     <key-property name="JobRef" column="JBH_JOB_REF" type="String(10)" /> 
     <key-property name="Status" column="JBH_STATUS" type="String(10)" /> 
    </composite-id> 
    <property name="RowId" column="TK_ROWID" type="Int32" not-null="true" /> 
    <property name="PropRef" column="JBH_PROP_REF" type="String(20)" not-null="false" /> 
    </class> 
</hibernate-mapping> 

而且房產測繪是這樣的:


<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> 
    <class name="Property" dynamic-update="true" table="PROPERTY"> 
    <composite-id> 
     <key-property name="Company" column="PRP_COMPANY" type="String(6)" /> 
     <key-property name="Reference" column="PRP_REFERENCE" type="String(20)" /> 
    </composite-id> 
    <property name="RowId" column="TK_ROWID" type="Int32" not-null="true" /> 
    <property name="Name" column="PRP_NAME" type="String(40)" not-null="false" /> 
    </class> 
</hibernate-mapping> 

在Jobheader它使用「PropRef」來保存「參考」屬性。

我想創建一個將被稱爲JobHeaderJoinedProperty 所以或許會是這個樣子了新的映射文件:


<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> 
    <class name="JobHeaderJoinProperty" dynamic-update="true" table="JOB_HEADER"> 
    <composite-id> 
     <key-property name="Company" column="JBH_COMPANY" type="String(6)" /> 
     <key-property name="ContractRef" column="JBH_CONTRACT_REF" type="String(10)" /> 
     <key-property name="JobRef" column="JBH_JOB_REF" type="String(10)" /> 
     <key-property name="Status" column="JBH_STATUS" type="String(10)" /> 
    </composite-id> 
    <property name="RowId" column="TK_ROWID" type="Int32" not-null="true" /> 
    <property name="PropRef" column="JBH_PROP_REF" type="String(20)" not-null="false" /> </class> 
    <bag name="Property" fetch="join" > 
     <key column="Reference" property-ref="PropRef" /> 
     <one-to-one class="Property"/> 
    </bag> 
    </class> 
</hibernate-mapping> 

然後希望那麼我JobHeaderJoinedProperty實體將能夠與訪問屬性實體它在這裏:


public virtual Property Property 
     { 
      get 
      { 
      return this.property; 
      } 
      set 
      { 
      this.property = value; 
      } 
     } 

通過nhibernate連接兩個遺留表不應該太棘手?

我真的只是想複製內部連接在SQL會是這樣:


Select * from job_header inner join property on property.reference = job_header.propref 

回答

0

是不是一個一對一的映射你是後?

<one-to-one 
     name="PropertyName"        (1) 
     class="Property"         (2) 
     cascade="all|none|save-update|delete"    (3) 
     constrained="true|false"       (4) 
     fetch="join|select"        (5) 
     property-ref="PropertyNameFromAssociatedClass"  (6) 
     access="field|property|nosetter|ClassName"   (7) 
/> 

所以你的情況這將是

<one-to-one 
     name="Property"        
     class="ClassName"         
     property-ref="PropRef" 
/> 

來源http://www.nhforge.org/doc/nh/en/#mapping-declaration-onetoone