Hi Ulf,
what you did in your bean is to use a Primary Key from the container
managed field already contained in the Bean. So the Primary Key will be
already initialized when the enterprise object is created.
I wanted to use a primary key which is automatically generated by the
database! So the key will not be initialized at creation-time.
In the spec I found the following passage:
"When defining the primary key for the enterprise bean, the Deployer may
sometimes need to subclass
the entity bean class to add additional container-managed fields (this
typically happens for entity beans
that do not have a natural primary key, and the primary keys are
system-generated by the underlying
database system that stores the entity objects)."
But unfortunately that's the only reference I have about how to use
primary keys generated by the database. Do you have a concrete idea how
to handle this within j2eesdk?
Stefan
[EMAIL PROTECTED] schrieb:
>
> use java.lang.Integer instead of int.
>
> > -----Original Message-----
> > From: Lauren Commons [mailto:[EMAIL PROTECTED]]
> > Sent: Thursday, June 29, 2000 6:03 PM
> > To: [EMAIL PROTECTED]
> > Subject: Re: How to create SQL statements within J2eeSdk if there
> > isnoPrim ary Key?
> >
> >
> > I assume the String in
> > > <prim-key-class>java.lang.String</prim-key-class>
> > corresponds to a char-type field in the database.
> > What if the primary key in the database table is not a
> > string? I have int fields, for instance.
> > > it also works with cmp. If you don't have a compound key
> > there is no need
> > > for an extra PK class
> > >
> > > <entity>
> > > <description />
> > > <display-name />
> > > <small-icon />
> > > <large-icon />
> > > <ejb-name>StructureFolder</ejb-name>
> > > <home>com.ceag.dms.server.StructureFolderHome</home>
> > > <remote>com.ceag.dms.server.StructureFolder</remote>
> > > <ejb-class>com.ceag.dms.server.StructureFolderBean</ejb-class>
> > > <persistence-type>Container</persistence-type>
> > > <prim-key-class>java.lang.String</prim-key-class>
> > > <reentrant>False</reentrant>
> > > <cmp-field>
> > > <description />
> > > <field-name>path</field-name>
> > > </cmp-field>
> > > <cmp-field>
> > > <description />
> > > <field-name>description</field-name>
> > > </cmp-field>
> > > <cmp-field>
> > > <description />
> > > <field-name>name</field-name>
> > > </cmp-field>
> > > <cmp-field>
> > > <description />
> > > <field-name>oid</field-name>
> > > </cmp-field>
> > > <primkey-field>oid</primkey-field>
> > > <ejb-ref>
> > > <description />
> > > <ejb-ref-name>ejb/docspace</ejb-ref-name>
> > > <ejb-ref-type>Entity</ejb-ref-type>
> > > <home>com.ceag.dms.server.DocSpaceHome</home>
> > > <remote>com.ceag.dms.server.DocSpace</remote>
> > > <ejb-link>DocSpace</ejb-link>
> > > </ejb-ref>
> > > <resource-ref>
> > > <description />
> > > <res-ref-name>StructureFolderDB</res-ref-name>
> > > <res-type>javax.sql.DataSource</res-type>
> > > <res-auth>Container</res-auth>
> > > </resource-ref>
> > > </entity>
> > >
> > > Ulf Gohde
> > >
> > >
> > > > -----Original Message-----
> > > > From: Stefan Hanenberg �mailto:shanenbe�INFORMATIK.UNI-ESSEN.DE�
> > > > Sent: Thursday, June 29, 2000 4:30 PM
> > > > To: EJB-INTEREST�JAVA.SUN.COM
> > > > Subject: Re: How to create SQL statements within J2eeSdk if there
> > > > isnoPrimary Key?
> > > >
> > > >
> > > > Hi Nail,
> > > >
> > > > thank you for your answer...but maybe I have to add that
> > my Bean is a
> > > > container-managed one (sorry, I forgot to say).
> > > >
> > > > Stefan
> > > >
> > > >
> > > >
> > > > "Nail A." schrieb:
> > > > >
> > > > > Hi Stefan,
> > > > > at first: the finder methods are defined in the home-interfaces
> > > > > (see section 8.3.2 of the EJB-Spec.1.1.)
> > > > >
> > > > > for example:
> > > > > public Account findByPrimaryKey(String user_id)
> > > > > throws FinderException, RemoteException;
> > > > > public Collection findByLastName(String name)
> > > > > throws FinderException, RemoteException;
> > > > > public Collection findInRange(double low, double high)
> > > > > throws FinderException, RemoteException;
> > > > >
> > > > > The Entity-EJB has to define one ejbFind�...�-method for
> > > > each of this methods.
> > > > > That means, that this methods contain calls to special
> > methods with
> > > > > SQL-Queries.
> > > > >
> > > > > example:
> > > > >
> > > > > public String ejbFindByPrimaryKey(String primaryKey)
> > > > > throws FinderException
> > > > > �
> > > > > System.out.println("ejbFindByPrimaryKey method");
> > > > > try �
> > > > > if (selectByPrimaryKey(primaryKey)) �
> > > > > return primaryKey;
> > > > > �
> > > > > else �
> > > > > throw new ObjectNotFoundException
> > > > > ("Row for id " + primaryKey + " not found.");
> > > > > �
> > > > > � catch (Exception ex) �
> > > > > throw new EJBException("ejbFindByPrimaryKey: " +
> > > > > ex.getMessage());
> > > > > �
> > > > > �
> > > > >
> > > > > last but not least:
> > > > >
> > > > > private boolean selectByPrimaryKey(String
> > primaryKey) throws
> > > > > java.sql.SQLException
> > > > > �
> > > > > System.out.println(" selectByPrimaryKey method");
> > > > > String selectStatement = "SELECT ID FROM TABLE
> > > > WHERE USER_ID = ? ";
> > > > > PreparedStatement prepStmt =
> > > > > (PreparedStatement)con.prepareStatement(selectStatement);
> > > > > prepStmt.setString(1, primaryKey);
> > > > > prepStmt.executeQuery();
> > > > > ResultSet rs = (ResultSet)prepStmt.executeQuery();
> > > > > boolean result = rs.next();
> > > > > prepStmt.close();
> > > > > return result;
> > > > > �
> > > > >
> > > > > Hope, this helps you to solve your problems.
> > > > > regards
> > > > > Nail
> > > > > - Dep.of CS -
> > > > > Univ. Hamburg
> > > > >
> > > > >
> > > > **************************************************************
> > > > *****************************
> > > > >
> > > > > Stefan Hanenberg wrote:
> > > > >
> > > > > > Hi,
> > > > > >
> > > > > > I have a question: I have an EntityBean without a primary
> > > > key-class. How
> > > > > > can I use it within the j2eesdk and cloudscape? The main
> > > > problem is:
> > > > > > What are the SQL-statements for ejbRemove() and
> > > > findByPrimaryKey()?
> > > > > >
> > > > > > Regards,
> > > > > > Stefan
> > > > > >
> > > > > >
> > > > ==============================================================
> > > > =============
> > > > > > To unsubscribe, send email to listserv�java.sun.com and
> > > > include in the body
> > > > > > of the message "signoff EJB-INTEREST". For general help,
> > > > send email to
> > > > > > listserv�java.sun.com and include in the body of the
> > > > message "help".
> > > > >
> > > > >
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