I usually keep my dao very fine grained (they look after a singular table). Ie each method of the dao only does one thing a singular insert, delete, select. my course grain service layer provides the exposed buiness logic which is made up of calls to the different dao required to perform that action. Sometimes this layer is a facade to the dao like for a insert opertaion that does not require a transaction or communication with other tables, again select are sometimes like this i.e it is a streight call from service -> dao. I find this a small price to pay for a conceptually easy to indersand and extensable service layer.
Anway back to transaction - using this design i have found it better to place all my transactions here in the service layer. -----Original Message----- From: Brandon Goodin [mailto:[EMAIL PROTECTED] Sent: Wed 5/25/2005 4:28 AM To: ibatis-user-java@incubator.apache.org Subject: Re: Transactions It certainly would be safer to always declare a transaction in your Service layer. Any time i perform an update, delete or insert i wrap it in a transaction, even if i know the underlying only makes one update/insert/delete. I think your conclusion is very sound. Brandon On 5/24/05, Lieven De Keyzer <[EMAIL PROTECTED]> wrote: > Sorry to pick this up again, but I still have got one question. > Wouldn't it be save to always wrap the calls in the service layer to the dao > layer, in transactions? If this would be the case: > > > accountDao.insertAccount(account); > > Dao Layer: > public void insertAccount(Account account) > { > update("insertAccount", account); > } > > There seems no need to use a startTransaction in the service layer, because > only one statement is executed. But if the insertAccount method would change > to: > > public void insertAccount(Account account) > { > update("insertAccount", account); > update("insertProfile", account); > update("insertSignon", account); > } > > I would have to alter de Service layer code. I think it's a bit weird and > violates the principles of OO. I guess I'm seeing this totally wrong? > > > > >I think we are getting in to splitting hairs here. The answer on where > >to put it would have to reside in whether you will be > >updating/inserting accounts from any other location and if it is a > >requirement that everytime you update/insert an account that you also > >update/insert a profile and a signon. There are probably a dozen other > >reasons i could come up with that would influence where to put it. My > >general rule on things like this is that I would push it up into the > >Service layer regardless because insertAccount, insertProfile and > >insertSignon are fine-grained calls that possible could be used > >outside of this block. But, like i said above... that judgment may > >change based on the "business rules". But, truly, i don't think there > >is an easy "this way is right" approach. > > >Brandon > > >On 5/24/05, Jason Hall <[EMAIL PROTECTED]> wrote: > >if a an error occurs in any of these 3 updates below > > > > update("insertAccount", account); > > > > update("insertProfile", account); > > > > update("insertSignon", account); > >a rollback will occur before the daoManager.commitTransaction(). > >So isn't it safe to say that these updates a wrapped in the transaction? > >Also doesn't this constitute a valid insert of Account? > > > >Example: > > > >Service Layer: > > > >doaManager.startTransaction(); > >accountDao.insertAccount(account); > >doaManager.commitTransaction(); > >.... > >finally(){doaManager.endTransaction():} > > > >Dao Layer: > >public void insertAccount(Account account) > >{ > >update("insertAccount", account); > >update("insertProfile", account); > >update("insertSignon", account); > >} > > > > > > > >-----Original Message----- > >From: Lieven De Keyzer [mailto:[EMAIL PROTECTED] > >Sent: Tuesday, May 24, 2005 3:48 PM > >To: [EMAIL PROTECTED]; ibatis-user-java@incubator.apache.org; > >[EMAIL PROTECTED] > >Subject: Re: transactions > > > > > > > > > > >From: Clinton Begin <[EMAIL PROTECTED]> > > >Reply-To: [EMAIL PROTECTED] > > >To: ibatis-user-java@incubator.apache.org, Brandon Goodin > > ><[EMAIL PROTECTED]> > > >Subject: Re: transactions > > >Date: Tue, 24 May 2005 13:40:04 -0600 > > > > > >Those update statements ARE in a transaction. But you should NEVER manage > > >transactions inside the DAO. The transaction in this case is taken care > >of > > >outside of the scope of this particular method (I believe in this case it > > >is > > >actually an automatic Ddo you have AO transaction, so you might not find > >the >calls to > > >start/commit/end). > > > >So, what you mean is: I should make the transaction in my service layer, > >and > >inside this transaction call the dao method. But if I change a method in my > >DAO, to have multiple statements, I would also need to change my Service > >class, to place the call in a transaction? > >And how does one specify those automatic transactions? > > > > > >Clinton > > > > > >On 5/24/05, Brandon Goodin <[EMAIL PROTECTED]> wrote: > > > > > > > > Message was sent to me privately... so i am posting it to the list > > > > ----- > > > > But for example, in the JPetStoreExample, in the AccountSqlMapDao, > >this > > >is > > > > a > > > > method: > > > > > > > > public void insertAccount(Account account) { > > > > update("insertAccount", account); > > > > update("insertProfile", account); > > > > update("insertSignon", account); > > > > } > > > > > > > > Aren't those different update statements better off in a transaction? > > >And > > > > why no different calls from the Service layer? > > > > I'm just trying to understand the difference. > > > > > > > > >From: Brandon Goodin <[EMAIL PROTECTED]> > > > > >Reply-To: Brandon Goodin <[EMAIL PROTECTED]> > > > > >To: ibatis-user-java@incubator.apache.org > > > > >Subject: Re: transactions > > > > >Date: Tue, 24 May 2005 12:45:59 -0600 > > > > > > > > > >It is not neccessary to call transactions on only one statement. > > > > > > > > > >Transactions should be handled on the Service layer and make more > > > > >fine-grained calls to the DAO layer. > > > > > > > > > >Brandon > > > > > > > > > >On 5/24/05, Lieven De Keyzer <[EMAIL PROTECTED]> wrote: > > > > > > At http://www.reumann.net/struts/ibatisLesson1/step6.do > > > > > > this is an example in a ibatis/struts tutorial > > > > > > > > > > > > public int update(String statementName, Object parameterObject) > > >throws > > > > > > DaoException { > > > > > > int result = 0; > > > > > > try { > > > > > > sqlMap.startTransaction(); > > > > > > result = sqlMap.executeUpdate(statementName, parameterObject); > > > > > > sqlMap.commitTransaction(); > > > > > > } catch (SQLException e) { > > > > > > try { > > > > > > sqlMap.rollbackTransaction(); > > > > > > } catch (SQLException ex) { > > > > > > throw new DaoException(ex.fillInStackTrace()); > > > > > > } > > > > > > throw new DaoException(e.fillInStackTrace()); > > > > > > } > > > > > > return result; > > > > > > } > > > > > > > > > > > > Is it necessary to have a transaction started for just 1 statement > > > > > > execution? > > > > > > > > > > > > Also, what's the better way? Doing a transaction in a Service > >class, > > > > >that > > > > > > has multiple DAO's, or doing it in the DAO class, doing different > > > > >statements > > > > > > in one method? Or is there no difference? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.
