This could be an option in CMP perhaps. -----Original Message----- From: Aaron Mulder [mailto:[EMAIL PROTECTED]] Sent: Friday, December 08, 2000 11:51 AM To: jBoss Subject: Re: [jBoss-User] Implementing an entity bean to access an Oracle sequence On Fri, 8 Dec 2000, Peter Schauss wrote: > Is it possible to access an Oracle sequence with an entity > bean using CMP or must I use BMP? > > If anyone has done this, can you post some sample code? There have been several extensive discussions about this on the mailing list. I'll repeat a few of the points, but you can also look through the archives: - There's not way for CMP to "do it for you" since there's so much variance across DBMSs - There are a number of ways to generate unique keys without hitting the sequence every time (grab a block of numbers, use some bits from the DB and some bits from the app server, etc.) - You can write an MBean that gets IDs from the sequence, so when a bean wants an ID it gets the generator MBean from JNDI and then asks for it. I think Rickard wrote an example of this that is in CVS somewhere (test beans?) - but it may require minor changes if you're using JBoss from CVS instead of JBoss 2.0. This is probably the most elegant solution, and can even incorporate the point above, but requires some familiarity with JMX MBeans, the JBoss config files, etc. - You can write a method in your CMP bean that gets the value from the sequence (using BMP-style DB calls). Then in your ejbCreate, call that method to generate the ID and put it in a field, which will be persisted via CMP after the ejbCreate returns. Whether you prefer this option or the previous one probably depends on how many sequences you're planning to use - this would be the "quick and dirty" solution. Aaron -- -------------------------------------------------------------- To subscribe: [EMAIL PROTECTED] To unsubscribe: [EMAIL PROTECTED] Problems?: [EMAIL PROTECTED] -- -------------------------------------------------------------- To subscribe: [EMAIL PROTECTED] To unsubscribe: [EMAIL PROTECTED] Problems?: [EMAIL PROTECTED]
