hibernate的inverse,cascade
/** * inverse:反转 * inverse=false 表示将关系的维护交给被控方来维护(让人民记住国家主席) * cascade:级联 * cascade=all ,表示对象发生改变,它所关联的对象也会发生改变 * save-update,delete,none(不级联默认值) */
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.itcast.b_one2Many"> <class name="Dept" table="t_dept"> <id name="deptId"> <generator class="native"></generator> </id> <property name="deptName" length="20"></property> <!-- 一对多关联映射配置 (通过部门管理到员工) Dept 映射关键点: 1. 指定 映射的集合属性: "emps" 2. 集合属性对应的集合表: "t_employee" 3. 集合表的外键字段 "t_employee. dept_id" 4. 集合元素的类型 inverse=false set集合映射的默认值; 表示有控制权 --> <set name="emps" cascade="save-update,delete" table="t_employee" inverse="true"> <!-- table="t_employee" --> <key column="dept_id"></key> <one-to-many class="Employee"/> </set> </class> </hibernate-mapping>
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.itcast.b_one2Many"> <class name="Employee" table="t_employee"> <id name="empId"> <generator class="native"></generator> </id> <property name="empName" length="20"></property> <property name="salary" type="double"></property> <!-- 多对一映射配置 Employee 映射关键点: 1. 映射的部门属性 : dept 2. 映射的部门属性,对应的外键字段: dept_id 3. 部门的类型 --> <many-to-one name="dept" column="dept_id" class="Dept"></many-to-one> </class> </hibernate-mapping>