-----Mensagem original----- De: Ron Grabowski [mailto:[EMAIL PROTECTED] Enviada em: terça-feira, 12 de julho de 2005 18:57 Para: agcunha Assunto: Re: Concurrency control using optimistic locking. The best way and how to implement...
http://www.mail-archive.com/[email protected]/msg00455.htm l Gilles' suggestion of having a Version column on your table may be a simple solution. You may be able to use this: http://www.tek-tips.com/faqs.cfm?fid=761 to return the number of rows affected by the UPDATE statement. I'm sure other people on the list would be interested in this discussion. You may want to forward my response to the list and continue the conversation there. - Ron --- agcunha <[EMAIL PROTECTED]> wrote: --------------------------------- Thanks Ron, Now I know How to implement the optimistic locking in my application. But I still have a question :-) I made the stored procedure above on SQL Server: CREATE PROCEDURE dbo.[ps_updateAccount] @Account_ID [int], @FirstName varchar(32), @LastName varchar(32), @Email varchar(128), @BannerOption varchar(255), @CartOption [int], @lastUpdate datetime AS DECLARE @AccountID int DECLARE @V_DAT_ATUALIZACAO datetime; declare @cur_account cursor set @cur_account = cursor for SELECT Account_ID FROM ACCOUNTS where [EMAIL PROTECTED] and lastupdate = @lastUpdate for update open @cur_account IF Cursor_Status('variable', '@cur_account') = 1 begin FETCH NEXT FROM @cur_account WHILE @@Fetch_Status != -1 BEGIN set @V_DAT_ATUALIZACAO = GetDate() UPDATE ACCOUNTS SET Account_FirstName = @FirstName, Account_LastName = @LastName, Account_Email = @Email, Account_Banner_Option = @BannerOption, Account_Cart_Option = @CartOption, lastupdate = @V_DAT_ATUALIZACAO WHERE CURRENT OF @cur_account FETCH NEXT FROM @cur_account end end else begin set @V_DAT_ATUALIZACAO = NULL; end close @cur_account deallocate @cur_account I made somes unit tests on nUnit to test concurrency. I could see that there is a code block on Update method of the SqlMapper class that is commented. // // check that statement affected a row // if( rows == 0 ) // { // // throw concurrency error if no record was affected // throw new ConcurrentException(); // } This code block is necessary to test concurrency and I saw that iBatis users had some problems with it on making record changes. I suggest to make an overload of this method to support Optimistic Locking. Like this: public int Update(string statementName, object parameterObject, bool useOptimisticLocking) This method will have the code that throws the exception uncommented. What about? Do you know where I can find the commented ConcurrentException class? Thanks a lot, Anderson
