Hibernate_映射簡單集合類型和組件集合類型

Hibernate_映射簡單集合類型和組件集合類型(組合關係中, 從對象可用String 代替或者可以做成組件), 映射demo如下:

<hibernate-mapping package="cd.itcast.day4.element">
	<class name="Product" table="product">
		<id name="id" column="id">
			<generator class="native"/>
		</id>
		<property name="name" column="name"/>
		<!-- 映射簡單類型的集合 -->
		<set name="colors" table="PRODUCT_COLOR">
			<key column="PRODUCT_ID"/>
			<element column="color" type="string"/>
		</set>
		
		<!-- 映射組件類型的集合 -->
		<list name="pcps" table="PRODUCT_COLOR_PRICE">
			<key column="PRODUCT_ID"/>
			<list-index column="SEQ"/>
			<composite-element class="ProductColorPrice">
				<property name="color" column="color"/>
				<property name="price" column="price"></property>
			</composite-element>
		</list>
	</class>
</hibernate-mapping>

另外, 介紹一下Hibernate 中,各種集合如何映射. Set 集合:

<hibernate-mapping package="cd.itcast.day3.one2many">
	
	<class name="Department" table="department">
		<id name="id" column="id">
			<generator class="native"/>
		</id>
		<property name="name" column="name"/>
		<!--inverse: one方是否放棄對many方的管理  -->
		<set name="employees" inverse="true">
			<key column="dept_id"/>
			<one-to-many class="Employee"/>
		</set>
	</class>
	
	<class name="Employee" table="employee">
		<id name="id" column="id">
			<generator class="native"/>
		</id>
		<property name="name" column="name"/>
		<many-to-one name="dept" column="dept_id" class="Department"/>
	</class>
</hibernate-mapping>

list 集合 和 bag 集合:

<hibernate-mapping package="cd.itcast.day3.one2many">
	
	<class name="Department" table="department">
		<id name="id" column="id">
			<generator class="native"/>
		</id>
		<property name="name" column="name"/>
		<!--inverse: one方是否放棄對many方的管理  
			在hibernate4.1之前,如果使用list, inverse不能爲true
		<list name="employees" inverse="true">
			<key column="dept_id"/>
			<list-index column="SEQ"></list-index>
			<one-to-many class="Employee"/>
		</list>
		-->
		
		<!-- bag可以看成無序的list, 只能用在list上 -->
		<bag name="employees" inverse="true">
			<key column="dept_id"/>
			<one-to-many class="Employee"/>
		</bag>
	</class>
	
	<class name="Employee" table="employee">
		<id name="id" column="id">
			<generator class="native"/>
		</id>
		<property name="name" column="name"/>
		<many-to-one name="dept" column="dept_id" class="Department"/>
	</class>
</hibernate-mapping>

Map 集合:

<hibernate-mapping package="cd.itcast.day3.one2many">
	
	<class name="Department" table="department">
		<id name="id" column="id">
			<generator class="native"/>
		</id>
		<property name="name" column="name"/>
		<!--inverse: one方是否放棄對many方的管理  
			在hibernate4.1之前,如果使用list, inverse不能爲true
		<list name="employees" inverse="true">
			<key column="dept_id"/>
			<list-index column="SEQ"></list-index>
			<one-to-many class="Employee"/>
		</list>
		-->
		
		<map name="employees" inverse="true">
			<key column="dept_id"/>
			<map-key column="map_key" type="string"/>
			<one-to-many class="Employee"/>
		</map>
	</class>
	
	<class name="Employee" table="employee">
		<id name="id" column="id">
			<generator class="native"/>
		</id>
		<property name="name" column="name"/>
		<many-to-one name="dept" column="dept_id" class="Department"/>
	</class>
</hibernate-mapping>