NHibernate Many to Many delete all my data in the table
- by Daoming Yang
I would love to thank @Stefan Steinegger and @David helped me out yesterday with many-to-many mapping.
I have 3 tables which are "News", "Tags" and "News_Tags" with Many-To-Many relationship and the "News_Tags" is the link table.
If I delete one of the news records, the following mappings will delete all my news records which have the same tags. One thing I need to notice, I only allowed unique tag stored in the "Tag" table.
This mapping make sense for me, it will delete the tag and related News records, but how can I implement a tagging system with NHibernate?
Can anyone give me some suggestion? Many thanks.
Daoming.
News Mapping:
<class name="New" table="News" lazy="false">
<id name="NewID">
<generator class="identity" />
</id>
<property name="Title" type="String"></property>
<property name="Description" type="String"></property>
<set name="TagsList" table="New_Tags" lazy="false" inverse="true" cascade="all">
<key column="NewID" />
<many-to-many class="Tag" column="TagID" />
</set>
</class>
Tag Mapping:
<class name="Tag" table="Tags" lazy="false">
<id name="TagID">
<generator class="identity" />
</id>
<property name="TagName" type="String"></property>
<property name="DateCreated" type="DateTime"></property>
<!--inverse="true" has been defined in the "News mapping"-->
<set name="NewsList" table="New_Tags" lazy="false" cascade="all">
<key column="TagID" />
<many-to-many class="New" column="NewID" />
</set>
</class>
