要点:
1.
<!--双向关联时要用:
inverse:由子表来维护关系,cascade:级联的关系 如果没有这个设置,
插入Customer成功(即使现在Order插入Order抛异常,这时产生了垃圾数据,
好的做法是用事务两者都能插入,避免垃圾数据的产生-->
<!--经测试:只需要在主表配置cascade="all",而子表不用配置cascade="all",
当删除主表实体时,子表的级联实体也会被删除-->
<!--cascade有4种??是吗??,分别表示级联操作的4种操作:
cascade = "none":
不能执行操作(有子时不给删父),经测试,为none时,添加父时没有自动添加子
cascade = "all" :
1.级联(删父时删子),经测试,为all时,添加父时自动添加子,
2.经测试,当设置cascade = "all",MS SQL
Server设置删除和更新操作虽然设置为:不执行操作,却被覆盖为联级
cascade = "null":
(删父时子设置为null),但经测试Nhibernate不支持这个值
cascade = "???": 删父时子设置为默认值-->
<set name="Orders" table="Order" generic="true"
inverse="true" cascade="all"><key column="CustomerId" foreign-key="FK_CustomerOrders"/>
<one-to-many class="Model.Order,Model"/>
</set>
2
Custmer.cs
1 using Iesi.Collections.Generic;
2 using System;
3 using System.Linq;
4 using System.Text;
5
6 namespace Model
7 {
8 public class Customer
9 {
10 public virtual int CustomerId{ get; set; }
11 public virtual String FirstName { get; set; }
12 public virtual String LastName { get; set; }
13
14 public virtual int Age { get; set; }
15 public virtual int Version { get; set; }
16
17 private ISet<Order> _orders = new HashedSet<Order>();
18 public virtual ISet<Order> Orders
19 {
20 get { return _orders; }
21 set { this._orders = value; }
22 }
23
24 }
25 }
Customer.hbm.xml
1 <?xml version="1.0" encoding="utf-8" ?>
2 <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
3 namespace="Model"
4 assembly="Model"
5 default-lazy="true">
6
7 <class name="Model.Customer, Model"
8 discriminator-value="0">
9 <!--unsaved-value="0" 主键表中不需要定义,而是需要在子表中定义-->
10 <id name="CustomerId"
11 column="CustomerId"
12 type="Int32"
13 unsaved-value="0">
14 <generator class="native" />
15 <!-- unsaved-value used to be null and generator was increment in h2.0.3 -->
16 </id>
17
18 <!--version标签必须放在Id后面,否则出错-->
19 <version name="Version"/>
20
21 <property name="FirstName" >
22 <column name="Firstname" length="50" not-null="true"/>
23 </property>
24
25 <property name="LastName" type="String">
26 <column name="Lastname"/>
27 </property>
28
29 <property name="Age" type="int">
30 <column name="Age"/>
31 </property>
32
33 <!--双向关联时要用:
34 inverse:由子表来维护关系,cascade:级联的关系 如果没有这个设置,
35 插入Customer成功(即使现在Order插入Order抛异常,这时产生了垃圾数据,
36 好的做法是用事务两者都能插入,避免垃圾数据的产生-->
37 <!--经测试:只需要在主表配置cascade="all",而子表不用配置cascade="all",
38 当删除主表实体时,子表的级联实体也会被删除-->
39 <!--cascade有4种??是吗??,分别表示级联操作的4种操作:
40 cascade = "none": 不能执行操作(有子时不给删父),经测试,为none时,添加父时没有自动添加子
41 cascade = "all" : 1.级联(删父时删子),经测试,为all时,添加父时自动添加子,
42 2.经测试,当设置cascade = "all",MS SQL Server设置删除和更新操作虽然设置为:不执行操作,却被覆盖为联级
43 cascade = "null": (删父时子设置为null),但经测试Nhibernate不支持这个值
44 cascade = "???": 删父时子设置为默认值-->
45 <set name="Orders" table="Order" generic="true"
46 inverse="true" cascade="all">
47
48 <key column="CustomerId" foreign-key="FK_CustomerOrders"/>
49 <one-to-many class="Model.Order,Model"/>
50 </set>
51 </class>
52 </hibernate-mapping>
Order.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace Model
{
public class Order
{
public virtual int OrderId { get; set; }
public virtual DateTime OrderDate { get; set; }
public virtual Customer Customer { get; set; }public virtual int Version { get; set; }
}
}
Order.hbm.xml
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="Model"
assembly="Model"
default-lazy="true"><!--table ="[Order]"因为Order是SQL关键字,表名如果不添加中括号[]会抛异常-->
<!--unsaved-value="0" 主键表中不需要定义,而是需要在子表中定义
unsaved-value id的类型是对象类型(如Int32等)unsaved-value不用显示标出来,因为unsaved-value默认值是null
unsaved-value默认值是null,
作用是:用于判断实体对象是新new的内存对象,还是应经持久化的对象,Nhibernate会从数据库中去获取
该实体对象的Id与unsaved-value的值比较(如果持久化,id不等于null,当然也就不等于默认值为unsaved-value):1.实体对象的Id与unsaved-value的值,相等,说明调用Save()添加,
2.实体对象的Id与unsaved-value的值,不相等相等,调用Update(),并在如果
-->
<class name="Model.Order, Model"
table ="[Order]"
discriminator-value="0" lazy="false">
<id name="OrderId"
column="OrderId"
type="Int32"
unsaved-value="0">
<generator class="native" />
<!-- unsaved-value used to be null and generator was increment in h2.0.3 -->
</id><!--version标签必须放在Id后面,否则出错-->
<!--<version name="Version"/>--><property name="OrderDate" type="DateTime" not-null="true">
<column name="OrderDate" />
</property><many-to-one name="Customer" not-null="true">
<column name="CustomerId" />
</many-to-one></class>
</hibernate-mapping>
01-03-02-1【Nhibernate (版本3.3.1.4000) 出入江湖】CRUP操作--cascade
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