转：hibernate映射视图的两种方式

本文转自：http://blog.csdn.net/id19870510/article/details/5453965

 

1.数据库已经建立视图，hibernate只是把视图当作普通的表来映射。

视图VIEW_MER_INST_POS:

select MER.DAYS_MERCHT_ID MER_ID,
       INST.DAYS_MERCHT_ID INST_ID,
       POS.POS_ID POS_ID
from tbl_days_mercht_attr MER,
     tbl_days_mercht_info INST,
     tbl_days_mercht_pos_info POS
where MER.days_mercht_id = INST.up_days_mercht_id
  and INST.days_mercht_id = POS.days_mercht_id 

 hbm.xml配置：

<class name="db.po.ViewMerInstPos" table="VIEW_MER_INST_POS"> 
	<composite-id>
		<key-property  name="merId" column="MER_ID" type="java.lang.String" length="8"/>
		<key-property  name="instId" column="INST_ID" type="java.lang.String" length="8"/>
		<key-property  name="posId"  column="POS_ID" type="java.lang.String" length="8"/>
	</composite-id>
</class>

 

2.数据库没有视图，用hibernate自己做视图映射：

hbm配置如下：

<hibernate-mapping package="huntersxp.db.pojo">
<class name="ViewMerInstPos">
<meta attribute="sync-DAO">false</meta>
<subselect>
select
MER.DAYS_MERCHT_ID MER_ID,INST.SHOP_NM SHOP_NM,POS.POS_ID POS_ID
from tbl_days_mercht_attr MER,
tbl_days_mercht_info INST,
tbl_days_mercht_pos_info POS
where MER.days_mercht_id = INST.up_days_mercht_id and INST.days_mercht_id = POS.days_mercht_id
</subselect>
<synchronize table="tbl_days_mercht_attr"/>
<synchronize table="tbl_days_mercht_info"/>
<synchronize table="tbl_days_mercht_pos_info"/>
<composite-id>
	<key-property name="merId" column="MER_ID" type="java.lang.String" length="8"/>
	<key-property name="shopNm" column="SHOP_NM" type="java.lang.String" length="40" />
	<key-property name="posId" column="POS_ID" type="java.lang.String" length="40"/>
</composite-id>
</class>
</hibernate-mapping>

  其中synchronize表示当表的数据发生变化的时候，视图的数据也会发生变化。