Question

我试图使用NHibernate映射多个子类级别，我必须承认我是新手。我映射的数据是网络数据包捕获。

基本上，我希望能够在数据库中的表上分割对象的不同继承级别，这样，例如，当我收到TCP数据包时，非常一般的数据（如时间戳）存储在'数据包表，更具体的数据存储在各自的表中，例如“IP”表中的IP标头和“TCP”表中的TCP标头。

我的映射

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="WindowsFormsApplication1.BasePacket, WindowsFormsApplication1" table="Packets" lazy="false">

    <id name="ID" column="ID">
      <generator class="identity" />
    </id>

    <property name="timeStamp" column="timeStamp" type="datetime"></property>

    <joined-subclass table="IP" name="WindowsFormsApplication1.IP, WindowsFormsApplication1" lazy="false">
      <key column="IPID"/>

      <property name="identification" column="identification" type="UInt16"></property>
      <property name="sourceIP" column="sourceIP" type="BinaryBlob" ></property>
      <property name="destinationIP" column="destinationIP" type="BinaryBlob"></property>
      <property name="version" column="version" type="int"></property>
      <property name="IPHeaderLength" column="IPHeaderLength" type="byte"></property>
      <property name="sizeOfDatagram" column="sizeOfDatagram" type="UInt16"></property>
      <property name="reserved" column="reserved" type="bool"></property>
      <property name="dontFragment" column="dontFragment" type="bool"></property>
      <property name="moreFragments" column="moreFragments" type="bool"></property>
      <property name="fragmentOffset" column="fragmentOffset" type="UInt16"></property>
      <property name="timeToLive" column="timeToLive" type="byte"></property>
      <property name="protocol" column="protocol" type="int"></property>
      <property name="headerChecksum" column="headerChecksum" type="UInt16"></property>
      <property name="additionalData" column="additionalData" type="BinaryBlob"></property>

      <joined-subclass table="TCP" name="WindowsFormsApplication1.TCP, WindowsFormsApplication1" lazy="false">
        <key column="TCPID"/>

        <property name="sourcePort" column="sourcePort" type="UInt16"></property>
        <property name="destinationPort" column="destinationPort" type="UInt16"></property>
        <property name="ISN" column="ISN" type="long"></property>
        <property name="ASN" column="ASN" type="long"></property>
        <property name="innerProtocolHeaderLength" column="innerProtocolHeaderLength" type="byte"></property>
        <property name="FIN" column="FIN" type="bool"></property>
        <property name="SYN" column="SYN" type="bool"></property>
        <property name="RST" column="RST" type="bool"></property>
        <property name="PSH" column="PSH" type="bool"></property>
        <property name="ACK" column="ACK" type="bool"></property>
        <property name="URG" column="URG" type="bool"></property>
        <property name="windowSize" column="windowSize" type="UInt16"></property>
        <property name="checksum" column="checksum" type="UInt16"></property>
        <property name="urgentPointer" column="urgentPointer" type="UInt16"></property>
        <property name="options" column="options" type="BinaryBlob"></property>
        <property name="payload" column="payload" type="BinaryBlob"></property>
        <property name="anomalies" column="anomalies" type="string"></property>
      </joined-subclass>

      <joined-subclass table="UDP" name="WindowsFormsApplication1.UDP, WindowsFormsApplication1" lazy="false">
        <key column="UDPID"/>

        <property name="sourcePort" column="sourcePort" type="UInt16"></property>
        <property name="destinationPort" column="destinationPort" type="UInt16"></property>
        <property name="length" column="length" type="UInt16"></property>
        <property name="checksum" column="checksum" type="UInt16"></property>
        <property name="payload" column="payload" type="BinaryBlob"></property>
      </joined-subclass>

      <joined-subclass table="ICMP" name="WindowsFormsApplication1.ICMP, WindowsFormsApplication1" lazy="false">
        <key column="ICMPID"/>

        <property name="type" column="type" type="byte"></property>
        <property name="code" column="code" type="byte"></property>
        <property name="checksum" column="checksum" type="UInt16"></property>
        <property name="additionalDataICMP" column="additionalDataICMP" type="BinaryBlob"></property>
      </joined-subclass>
    </joined-subclass>
  </class>
</hibernate-mapping>

当我尝试使用此映射运行我的程序时，我收到此错误消息，或类似的引用不同的子类。

* NHibernate.dll中发生了'NHibernate.Exceptions.GenericADOException'类型的未处理异常

其他信息：无法插入：[WindowsFormsApplication1.UDP] [SQL：INSERT INTO数据包（timeStamp）VALUES（？）; SELECT LAST_INSERT_ID（）] *

我确信这只是因为我对NHibernate缺乏了解，并且非常感谢你的帮助。

Answer 1

您的标识列（ID）是否在数据库中实际定义为自动增量/标识？

您的时间戳是数据库时间戳列吗？如果它是你需要access =“readonly”因为nhibernate试图插入它。

此外，您的第一个加入的子类缺少或者它似乎在最后一个ICMP表之后的错误位置..除非我想念您的意图并且您希望它们嵌套。

使用多个子类NHibernate映射类

1 个答案: