Author: arminw
Date: Thu Aug 17 09:14:58 2006
New Revision: 432275
URL: http://svn.apache.org/viewvc?rev=432275&view=rev
Log:
fix OJB-96
Modified:
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/guides/sequencemanager.xml
Modified:
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/guides/sequencemanager.xml
URL:
http://svn.apache.org/viewvc/db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/guides/sequencemanager.xml?rev=432275&r1=432274&r2=432275&view=diff
==============================================================================
---
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/guides/sequencemanager.xml
(original)
+++
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/guides/sequencemanager.xml
Thu Aug 17 09:14:58 2006
@@ -97,10 +97,10 @@
<section>
<title>since OJB 1.0.4</title>
<p>
- OJB no longer assign the PK values of transient
objects on creation of
- the <a href="ext:identity"><code>Identity</code></a>
objects (using
+ OJB no longer assign the PK values of
<strong>transient objects</strong> on creation of
+ <a href="ext:identity"><code>Identity</code></a>
objects (using
<a
href="ext:identity-factory"><code>IdentityFactory</code></a>).
- The <code>Identity</code> object of a transient
persistence capable object
+ The <code>Identity</code> object of a <em>transient
persistence capable object</em>
is completely independent of the "real" primary key
assigned on insert
of the object - when calling
</p>
@@ -108,7 +108,7 @@
Identity oid = broker.serviceIdentity().buildIdentity(object);]]></source>
<p>
the specified persistence capable object will not be
modified and the
- returned <code>Identity</code> object use transient
primary key placeholder.
+ returned <code>Identity</code> object use
<em>transient primary key placeholders</em>.
</p>
<p>
The reason for doing this was to "harmonize" the
behavior of OJB when
@@ -118,9 +118,23 @@
it's not possible to lookup the generated PK value
before
the object is written to database.
</p>
- <p>
-
- </p>
+
+ <anchor id="forceBackward"/>
+ <section>
+ <title>Backward compatibility: Force the assignment of
PK fields while Identity creation</title>
+ <p>
+ To be backward compatible with older versions of
OJB it's still possible to force the
+ assignment of PK fields while Identity creation
before the object was made persistent,
+ using the an specific Identity constructor
(instead of the
+ <code>IdentityFactory</code> described in above
sections).
+ </p>
+ <source><![CDATA[
+Identity oid = new Identity(object, broker);]]></source>
+ <note>
+ But it's strongly recommended to avoid these calls
to avoid the drawbacks described above.
+ This call will be illegal in future versions of
OJB.
+ </note>
+ </section>
</section>
<anchor id="before-1.0.4"/>
@@ -130,25 +144,28 @@
By default OJB triggers the computation
of unique ids during calls to PersistenceBroker.store(...).
Sometimes it will be necessary to have the ids computed in
advance,
- before a new persistent object was written to database.
+ <strong>before</strong> a new persistent object was
written to database.
This can be done by simply obtaining the Identity of the
respective object as
follows:
</p>
<source><![CDATA[
-Identity oid = broker.serviceIdentity().buildIdentity(object);]]></source>
+Identity oid = broker.serviceIdentity().buildIdentity(object);
+or
+Identity oid = new Identity(object, broker);]]></source>
<p>
This creates an <a
href="ext:api/identity"><code>Identity</code></a> object for the
- new persistent object and set all primary key values of
the new persistent object
- - But it only works if <a
href="#autoincrement"><code>autoincrement</code></a>
+ transient object and set all primary key values. But this
only works if
+ <a href="#autoincrement"><code>autoincrement</code></a>
is enabled for the primary key fields.
</p>
<warning>
Force computation of unique values is not allowed when
using <em>database based
Identity columns</em> for primary key generation (e.g via
<a href="#identity-columns">Identity column supporting
sequence manager</a>), because the
- <em>real</em> PK value is at the earliest available after
database insert operation. If you
- nevertheless force PK computing, OJB will use an temporary
dummy PK value in the
- Identity object and this may lead to unexpeted behavior.
+ <em>real</em> PK value is at the earliest available after
database insert operation
+ (never for transient objects). If you
+ nevertheless force PK computing, OJB will use temporary
dummy PK values in the
+ transient object and created Identity instance - this may
lead to unexpeted behavior.
</warning>
<p>
Info about lookup persistent objects by primary key fields
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
