hmm, that's bad news for me. to my understanding that means that there won't
be a change of this behaviour very soon (let's say: never)?
If you know that an object needs 'update' you could use PB.store(obj, ObjectModificationDefaultImpl.UPDATE);
i know a workaround for my implementation (using some default identifier for locale, e.g. "DEFAULT") but that doesn't make me happy as i need to change data PLUS my code to work together in changing data, which makes it very error-prone if somebody misuses the classes provided by my applicationen.
by the way: from an sql perspective, an empty string (or varchar) is a valid primary key... (i know this is not a very subtile attempt but who knows ;-) )
I know, the problem is that method BrokerHelper#representsNull(...) is used to reduce DB calls and OJB use the rules:
<snip>
- If given value is 'null' itself, true will be returned
- If given value is instance of Number with value 0 and the field-descriptor represents a primitive field, true will be returned
- If given value is instance of String with length 0 and the field-descriptor is a primary key, true will be returned
</snip>
Currently it's not possible to bypass this test. Would it be useful to make this check configurable/pluggable?
regards, Armin
kr, guenther
-- Günther Wieser
creative-it Guglgasse 6/1/11/1 A-1110 Wien Austria http://www.creative-it.com
-----Ursprüngliche Nachricht-----
Von: Armin Waibel [mailto:[EMAIL PROTECTED] Gesendet: Montag, 28. Februar 2005 20:29
An: OJB Users List
Betreff: Re: problem with compound primary key when one key=""
Hi Günther,
> maybe the broker does something unexpected with the empty "" string? any
ideas?
When storing an object with PB.store(obj), OJB has to decide if an insert or update is required. Thus if the PK field is of type String and the value is 'null' or an empty String, OJB assume that the PK value was not set and declare the object as 'new'.
regards, Armin
Günther Wieser wrote:
hi,
i found a problem with using a compound primary key (two columns). it appears only if one of the keys is set to "" (an empty string, NOT!!!!
null).
here's my setup:
ojb 1.0.1, mysql 4.0.23 on XP prof., jdk 1.4.2_07
repository.xml: <class-descriptor class="com.creative_it.webcreator.resources.Property" table="properties"> <field-descriptor id="1" name="key" column="id" jdbc-type="VARCHAR" primarykey="true" indexed="true"/> <field-descriptor id="2" name="locale" column="locale" jdbc-type="VARCHAR" primarykey="true" indexed="true"/> <field-descriptor id="3" name="value" column="value" jdbc-type="VARCHAR" /> </class-descriptor>
the database layout: +--------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+--------------+------+-----+---------+-------+ | id | varchar(255) | | PRI | | | | value | text | YES | | | | | locale | varchar(255) | | PRI | | | +--------+--------------+------+-----+---------+-------+
example code:
Property prop = new Property();
prop.setKey("whateverKey");
prop.setLocale("");
prop.setValue("some test value");
broker.beginTransaction();
// this one works if table doesn't have one element with same key and locale
broker.store(prop);
broker.commitTransaction();
prop.setValue("a new value");
broker.beginTransaction();
// this one fails with the following exception
broker.store(prop);
broker.commitTransaction();
the exception raised is:
org.apache.ojb.broker.KeyConstraintViolatedException: SQL failure while insert object data for class com.creative_it.webcreator.resources.Property,
PK of the given object is [ key=test.property locale=], object was [EMAIL PROTECTED], exception message is [Duplicate key or integrity constraint violation message from
server:
"Duplicate entry 'test.property-' for key 1"] at org.apache.ojb.broker.accesslayer.JdbcAccessImpl.executeInsert(JdbcAcc essImp l.java:239) at org.apache.ojb.broker.core.PersistenceBrokerImpl.storeToDb(Persistence Broker Impl.java:1642) at org.apache.ojb.broker.core.PersistenceBrokerImpl.store(PersistenceBrok erImpl .java:1557) at org.apache.ojb.broker.core.PersistenceBrokerImpl.store(PersistenceBrok erImpl .java:715) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.store(Delegatin gPersi stenceBroker.java:175) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.store(Delegatin gPersi stenceBroker.java:175) at com.creative_it.webcreator.junit.resources.PropertyTest.testProperty(P ropert yTest.java:63) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.j ava:39 ) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccess orImpl .java:25) at java.lang.reflect.Method.invoke(Method.java:324) at junit.framework.TestCase.runTest(TestCase.java:154) at junit.framework.TestCase.runBare(TestCase.java:127) at junit.framework.TestResult$1.protect(TestResult.java:106) at junit.framework.TestResult.runProtected(TestResult.java:124) at junit.framework.TestResult.run(TestResult.java:109) at junit.framework.TestCase.run(TestCase.java:118) at junit.framework.TestSuite.runTest(TestSuite.java:208) at junit.framework.TestSuite.run(TestSuite.java:203) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(Remote TestRu nner.java:421) at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.
java:305) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTest Runner .java:186)
if i update the database entry with native SQL (e.g. UPDATE properties SET value="another value" WHERE id="whateverKey" AND locale="") everything works fine, so i'm pretty sure it is not a database problem or
database error.
also everything works fine if "locale" is set to e.g. "de_AT" or anything else except an empty string.
maybe the broker does something unexpected with the empty "" string? any ideas?
kr, guenther
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