有主键自增长，解决插入失败

--Hibernate中关于持久化类的配置  注意id下Generator子节点 class属性配置为native
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
    <class name="TestHibernateExpre.Entities.OrderListModel,TestHibernateExpre" table="OrderList">
        <id name="Orderid" column="id" type="int">
            <!--id中参数的设置问:native/assigned/foreign/increment-->
            <generator class="native"></generator>
        </id>
      </class>