Hi Jens, You're right. That's means this setup won't work. If the Log and LogReceiveItem persisting to different table then it should be ok. Haven't try, just guessing.
How to configure the repository to enable two classes(Log and LogReceiveItem, if LogReceiveItem inherit from Log) to persist to the same table with LOG_ID as primary key? Regards, Stephen >-----Original Message----- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >Sent: 28 May 2003 17:52 >To: OJB Users List; Stephen Ting Tiew Ung >Subject: Re: 1 to N mapping problems > > >Hi Stephen, > >see comments below... > >On Wed, May 28, 2003 at 05:13:28PM +0800, Stephen Ting wrote: >> The relationship of the classes are >> >> LogReceiving ----> 1:N LogReceivingItem ---> Log >> >> The LogReceivingItem object actually reference to Log >object. If I don't >> reference it to Log object. It's run perfectly. Whereas if I >include the >> <reference-descriptor> to Log object it will failed because >of multiple >> insert at LOG table with the same primary key. From the SQL generated >> trace I found that OJB generate the following SQL command. >> >> 1. INSERT INTO LOG_RECEIVING (with attributes of LogReceiving) >> 2. INSERT INTO LOG (with attributes of LOG) >> 3. UPDATE LOG_RECEIVING (with attributes of LogReceiving) >> 4. UPDATE LOG (with attributes of LogReceiving) >> 5. INSERT LOG (with attributes of LogReceivingItem) >> >> The java code I used to persist the LogReceiving object are as follow >> >> Implementation odmg = OJB.getInstance(); >> Database db = odmg.newDatabase(); >> try{ >> LogReceiving document = createDoc(); >> db.open("site1", Database.OPEN_READ_WRITE); >> Transaction tx = odmg.newTransaction(); >> tx.begin(); >> tx.lock(document, Database.OPEN_READ_WRITE); >> tx.commit(); >> >> }catch(ODMGException e){ >> throw new BDException(e.getMessage()); >> } >> >> <class-descriptor >> class="model.Log" table="LOG" > >> <field-descriptor >> name="logId" >> column="LOG_ID" >> jdbc-type="INTEGER" >> primarykey="true" >> autoincrement="true" >> /> >> </class-descriptor> >> >> <class-descriptor >> class="model.LogReceiving" >> table="LOG_RECEIVING"> >> <field-descriptor >> name="logReceivingId" >> column="LOG_RECEIVING_ID" >> jdbc-type="INTEGER" >> primarykey="true" >> autoincrement="true" >> /> >> >> <collection-descriptor >> name="lineItem" >> element-class-ref="model.LogReceivingItem" >> auto-retrieve="true" >> auto-update="false" >> auto-delete="true"> >> <inverse-foreignkey field-ref="logReceivingId"/> >> </collection-descriptor> >> </class-descriptor> >> >> <class-descriptor >> class="model.LogReceivingItem" table="LOG"> >> <field-descriptor >> name="logReceivingId" >> column="LOG_RECEIVING_ID" >> jdbc-type="INTEGER" >> /> >> <field-descriptor >> name="logId" >> column="LOG_ID" >> jdbc-type="INTEGER" >> /> > >I think you should declare logId as primary key here, too (just as you >did for model.Log above). > >> <reference-descriptor >> name="logReceiving" >> class-ref="model.LogReceiving" >> auto-retrieve="true" >> auto-update="true" >> auto-delete="true"> >> <foreignkey field-ref="logReceivingId"/> >> </reference-descriptor> >> <reference-descriptor >> name="log" >> class-ref="model.Log" >> auto-retrieve="true" >> auto-update="true" >> auto-delete="true"> >> <foreignkey field-ref="logId"/> >> </reference-descriptor> > >Imho this reference won't work. >Imagine you create an instance of LogReceivingItem associated with an >instance of Log. >log.logId then is equal to logReceivingItem.logId. >Now what happens when you try to insert both items into db ? Two >insert-Statements are generated, both for table LOG, and both with the >same value for LOG_ID, which I suppose to be the primary key in table >LOG. > > >hth, >Jens > >--------------------------------------------------------------------- >To unsubscribe, e-mail: [EMAIL PROTECTED] >For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
