Andrej Koelewijn

I wrote a small article about the upcoming Oracle World 2003 conference.

OptimalJ currently doesn’t generate code for database sequences which you can use to create unique values for primary keys in your tables.

So I did some research to see how other people solve this problem. One person suggested counting the number of records in a table, increase that number by one, and use that as your primary key. Brilliant! Should perform really well, and no concurrency problems to be expected.

I found one real solution on the optimalj forum, which was to create a Domain class (this translates into a database table) that holds ‘sequence’ records. One record per sequence, with a name and a value column. Then on the Domain Class you can add a DomainOperation to query the next sequence value, e.g., nextVal. The example on the forum described the situation when using EJBs, but I’m trying to generate DAOs, because i don’t have the memory in my laptop to run an ejb container.

After generating the application model and the code model i have to implement the code for the nextVal operation (get current value from table, add one, etc), but there’s a problem. Where is it? I can’t find the nextval stub anywhere, i must have checked 20 java files…