How to prevent writting primary key

benkarsa Oct 25, 2002 8:52 AM

Hi,

I'm new to EJB and so I've some problems.
I'm using JBoss 3.0.0 with MS SQL Server 2000 and JBuiler 6 EE. To write data to database I'm using CMP. Now I have a table which uses an IDENTITY (autogenerated primary key) field as Primary Key. Is it possible to prevent the CMP to write the Primary Key? My CMP always generates an INSERT statement which includes the Primary Key field. Given that I don't set the Primary Key in the CMP, the CMP always writes NULL into the table. This results in an error. Can anybody help me?

1. Re: How to prevent writting primary key

joe_k Oct 26, 2002 6:21 AM (in response to benkarsa)

Hi Sascha,

JBoss3.0.x does not support primary keys auto generated by the database for CMP. Maybe this feature will be implemented in a future version but currently it is not supported. If this is an option, try to implement your own PK generation strategy. If you are not sure on how to do this, see http://www2.theserverside.com/books/EJBDesignPatterns/index.jsp (Part1, Chapter5).

Greetings,
Jürgen
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2. Re: How to prevent writting primary key

joe_k Oct 26, 2002 6:30 AM (in response to benkarsa)

Hi Sascha,

JBoss3.0.x does not support primary keys auto generated by the database for CMP. Maybe this feature will be implemented in future versions but currently it is not possible to do so. If this is an option, try to implement your own pk generation strategy. If you are not sure about how to do this, see http://www2.theserverside.com/books/EJBDesignPatterns/index.jsp (Part1, Chapter5 for possible design patterns and the appendix for a sample implemention of the sequence blocks pattern).

Greetings,
Jürgen
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