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From t...@apache.org
Subject cvs commit: db-ojb/xdocs tutorial3.xml
Date Sat, 13 Dec 2003 21:48:27 GMT
thma        2003/12/13 13:48:27

  Modified:    xdocs    tutorial3.xml
  Log:
  provide more explanation for the auto-* flags
  
  Revision  Changes    Path
  1.31      +51 -7     db-ojb/xdocs/tutorial3.xml
  
  Index: tutorial3.xml
  ===================================================================
  RCS file: /home/cvs/db-ojb/xdocs/tutorial3.xml,v
  retrieving revision 1.30
  retrieving revision 1.31
  diff -u -r1.30 -r1.31
  --- tutorial3.xml	27 Oct 2003 18:17:05 -0000	1.30
  +++ tutorial3.xml	13 Dec 2003 21:48:27 -0000	1.31
  @@ -748,32 +748,76 @@
   specified default values are assumed:</p>
   <OL>
       <LI>
  -      On materializing an Object from the RDBMS with
  -      <code>PersistenceBroker.getObjectByQuery(...)</code>all
  -      its referenced objects (both 1:1 and 1:n associations) are
  +	  <b><code>auto-retrieve="true"</code></b><br/>
  +      By default materializing an Object from the RDBMS with
  +      <code>PersistenceBroker.getObjectByQuery(...)</code> cause all
  +      its referenced objects (both 1:1 and 1:n associations) to be
         materialized as well.
         (If OJB is configured to use proxies, the referenced objects are
         not materialized immmediately, but lazy loading proxy objects are used
         instead.)
       </LI>
       <LI>
  +	  <b><code>auto-update="false"</code></b><br/>
         On updating or inserting an object with
         <code>PersistenceBroker.store(...)
  -      </code>referenced objects are NOT updated by default.
  +      </code>referenced objects are NOT updated by default.  
       </LI>
       <LI>
  +	  <b><code>auto-delete="false"</code></b><br/>
         On deleting an object with <code>PersistenceBroker.delete(...)
         </code>referenced objects are NOT deleted by default.
       </LI>
   </OL>
   <p>
  -	If these default values are to be used, no special settings have to be
  -	made in the reference-descriptor or collection-descriptor elements.
  +	If no special settings are
  +	made in the reference-descriptor or collection-descriptor elements,
  +	these default settings are used.
   </p>
   <p>
   	<b>These default settings are mandatory for proper operation of the ODMG
   	and JDO implementation.</b>
   </p>
  +
  +<p>
  +	The default settings can be changed as follows:
  +	<OL>
  +		<LI>
  +			<b><code>auto-retrieve="false"</code></b><br/>
  +			With this setting references and and Collection attributes 
  +			will not be loaded by OJB on loading instances.
  +			OJB will also not replace those attributes with dynamic proxies.
  +			These attributes simply stay set to <code>null</code>.
  +			If such attributes must be accessed later, the user is responsible 
  +			to load them manually with the 
  +			<code>PersistenceBroker.retrieveReference(...)</code> 
  +			<code>PersistenceBroker.retrieveAllReferences(...)</code>  methods.
  +		</LI>
  +		<LI>
  +			<b><code>auto-update="true"</code></b><br/>
  +			If this flag is set on a reference- or collection-attribute
  +			the referenced objects are also persisted (inserted or updated) to the database.
  +			Objects that have been removed from collections are not automatically
  +			handled by the PersistenceBroker.
  +			By using special collections like the RemovalAwareCollection you can 
  +			achieve automatic handling of deletion from collections. 
  +		</LI>
  +		<LI>
  +			<b><code>auto-delete="true"</code></b><br/>
  +			If this flag is set on a reference- or collection-attribute
  +			the referenced objects are also deleted if an instance of
  +			the persistent class is deleted.
  +			The PersistenceBroker does <b>not</b> provide a full cascading delete,
  +			but does only remove objects that are actually referenced.
  +			Assume you load a master object that has a collection of 5 detail items
  +			and remove 2 of them. If the master object is deleted only the three
  +			remaining detail items are deleted. As the other two detail items
  +			are not deleted, this could result in foreign key violations
  +			if handled carelessly.
  +		</LI>		
  +	</OL>
  +</p>
  +
   <p>
   	In the following code sample, a reference-descriptor and a collection-descriptor
   	are configured to use cascading retrieval (<code>auto-retrieve="true"</code>),
  
  
  

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