Yes, until 3.0 the logic in Cayenne worked like this:
1. if you don't map PK as an object property, Cayenne will generate
the PK.
2. if you do map it, you must provide it yourself.
(3.0 relaxed this restriction, but 3.0 is not officially released yet)
Do not add the id to the properties exposed by the autogenerated
object.
Just add the id property to the class extending your autogenerated
class
and use
DataObjectUtils.pkForObject(this);
That's my preferred approach too. It is an extended version of #1
above. To expand on Christian's example, here is a full class:
public class MyClass extends _MyClass {
public int getId() {
return DataObjectUtils.intPKForObject(this);
}
}
Andrus
On Feb 1, 2007, at 5:00 PM, Christian Mittendorf wrote:
Hi!
Do not add the id to the properties exposed by the autogenerated
object.
Just add the id property to the class extending your autogenerated
class
and use
DataObjectUtils.pkForObject(this);
to return the pk for the object (may or may not work, I'm not sure how
auto_increment is handled by Cayenne in this case).
As an alternative, you may want to define another key for accessing
the
object. In that case you have to make sure that this reference to the
object is a) unique and b) that the property is set if the object is
newly created:
public void setPersistenceState(int state)
{
super.setPersistenceState(state);
// if the object was just created, set initial values
if (state == PersistenceState.NEW)
{
// Set all initial values here
Timestamp now = new Timestamp(System.currentTimeMillis());
String digest = "" + this.hashCode() + now.getTime();
this.setRecordCreated(now);
this.setExternalReference(MD5.getDigestAsHex(digest));
}
}
Make the property "external_reference" a unique key. This does also
secure
your application as the user cannot increment the id to see some
other objects
that he may not be allowed to see, if this kind of security is of
interest.
Christian
Am 01.02.2007 um 15:38 schrieb Frank:
Yes,
I get this error:
Validation failure for stemc.cayenne.Employees.id: "id" is required.
Frank
----- Original Message ----- From: "Peter Schröder"
<[EMAIL PROTECTED]>
To: <user@cayenne.apache.org>
Sent: Thursday, February 01, 2007 9:31 AM
Subject: AW: New user PK id question
did you set the pk-generation properly (database-generated) in the
modeler?
-----Ursprüngliche Nachricht-----
Von: Frank [mailto:[EMAIL PROTECTED]
Gesendet: Donnerstag, 1. Februar 2007 15:23
An: user@cayenne.apache.org
Betreff: New user PK id question
Hello,
I have a mysql table with a PK of id that is auto incremented.
The getter is not generated for this pk.
I need to use the pk id in a table as a link to allow the user to
edit.
If I add the pk id to the objEntity, whenever I try to add a
record, cayenne complains that the pk id field cannot be blank
I assign a value of 1 to the pk id and I can save the record.
When I look at the record just added, the pk id show the correct
value assigned by mysql(not 1)
What am I doing wrong?
I need theh id to add to the link.
Thanks
Frank
