O-R Mapping Features - Code snippets

Entity-deployment tag - sample code snippet

<entity-deployment name="HotelHome" location="HotelHome" table="Hotels" data-source="jdbc/OracleDS"> 

            location            =  JNDI name for the entity bean object

            table                =  Name of the table in the database into which this entity bean is persisted

                                       If Test table is not present in the database, a new Test table will be created. Otherwise, the same table will be used.

            data-source      =  JNDI name for the data source object 

Simple objects and primitive data type mapping - sample code snippet

<cmp-field-mapping name="m_FirstName" persistence-name="FirstName" /> 

             name                   =  name of the entity bean field

             persistence-name =  name of the database column into which the entity bean field is persisted

User defined serializable object mapping - sample code snippet

<cmp-field-mapping name="m_reservationDetails">
  <fields>
      <cmp-field-mapping name="m_arrivalDate" persistence-name="ARRIVAL_DATE" />
      <cmp-field-mapping name="m_numberOfNights" persistence-name="NO_OF_NIGHTS" />
      <cmp-field-mapping name="m_numberOfRooms" persistence-name="NO_OF_ROOMS" />
  </fields>

</cmp-field-mapping> 

           fields                 =   For grouping fields which are declared in the entity bean. Since m_reservationDetails is a user-defined serializable object which contains more than one field, <fields> tag is used to mention that.

Entity reference mappings - sample code snippet

<cmp-field-mapping name="m_hotel">

  <entity-ref    home="HotelHome">
    <cmp-field-mapping name="m_hotel"  persistence-name="HOTEL_ID" />
  </entity-ref>
</cmp-field-mapping> 

            home                =    JNDI name of the entity bean to be mapped

Collection object mapping - sample code snippet

<cmp-field-mapping name="m_facilities">

  <list-mapping table="hotel_facilities">
    <primkey-mapping>
      <cmp-field-mapping name="m_hotelID" persistence-name="HOTEL_ID" />
    </primkey-mapping>
    <value-mapping type="HotelFacility">
      <cmp-field-mapping>
        <fields>
          <cmp-field-mapping name="m_facilityType" persistence-name="FACILITY_TYPE"    />
          <cmp-field-mapping name="m_name"  persistence-name="FACILITY_TYPE_NAME"    />
          <cmp-field-mapping name="m_text" persistence-name="FACILITY_TEXT " />
        </fields>

      </cmp-field-mapping>
    </value-mapping>
  </list-mapping>
</cmp-field-mapping>  

           m_facilities        =   This is an List object that is to be mapped to a table. This list object holds HotelFacility user defined serializable object. Attributes of HotelFacility object are persisted in hotel_facility table.