What I generally do when this is a requirement is have an accumulator table that holds the next number in the sequence. When I need to fetch the next number, I do this:
Ensure a transaction exists Lock the row with the number I need (via LockMode.Upgrade) Read the number Increment the number Set the number on my domain object Commit the transaction This ensures that there are no gaps in the number sequence, as if the transaction fails and rolls back the next transaction will be able to pick up where the last successful transaction left off. From: [email protected] [mailto:[email protected]] On Behalf Of Tuna Toksoz Sent: Monday, January 04, 2010 9:14 AM To: [email protected] Subject: Re: [nhusers] Advice : Generate number This kind of key generation sounded like a business concern to me. Thoughts? Tuna Toksöz Eternal sunshine of the open source mind. http://devlicio.us/blogs/tuna_toksoz http://tunatoksoz.com http://twitter.com/tehlike On Mon, Jan 4, 2010 at 6:01 PM, José F. Romaniello <[email protected]<mailto:[email protected]>> wrote: A web application is a very concurrent environment, so you will need some kind of pessimistic lock. Instead of handling this at application level, I would choose doing this work in the database. Where? in a trigger :) Then set both Update and Insert as false for the column. 2010/1/4 Kris-I <[email protected]<mailto:[email protected]>> Hello, I have to generate an "invoice number", this number has the fomat YYYY/XXXX (YYYY is the year), XXXX is a number. The XXXX must be number without hole (1,2,3,4, ...) and no (1,3,4,..). It's a web application, is there a best practice to do this with NH ? Thanks, -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]<mailto:[email protected]>. To unsubscribe from this group, send email to [email protected]<mailto:nhusers%[email protected]>. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en. -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]<mailto:[email protected]>. To unsubscribe from this group, send email to [email protected]<mailto:nhusers%[email protected]>. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en. -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en. -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en.
