Robert,
Depends on if you need incrementally unique identifiers, or if you need just need a unique number. I have situations where I need unique "transaction ids", but they don't have to be ordered in any particular manner. I use java's random number generation facilities to generate a random number, then attempt to select a datarow from the database with that number; if I successfully select one, the number isn't unique and the process is repeated until I get a unique number. I use 9 digit numbers, so the likelihood of ever generating the same number twice is very small, and in practice, the loop never gets executed twice.
I see your point. This is an open issue right now but I think the client will want to have some sort of sequential numbering system. That is why I thought of employing the MySQL MAX() and then incrementing in the code.
I am doing more reading and there appears to be Cayenne support for Jakarta Velocity #bind and #result directives but I haven't got my demo code to work yet so I don't know if this is the solution for a non-mapped result set.
Joe
