If it's a concern, I'd stick with XML. But in my 12 years in this business, I've never swapped out one database wholesale for another.
Clinton 2010/2/19 Ing. Jan Novotný <novotn...@gmail.com> > Thanks. Did you notice my question about DB dialect porting issues? What is > your opinion on this matter? > > Jan > > > 2010/2/19 Clinton Begin <clinton.be...@gmail.com> > >> There will be a new release by then, probably this weekend. >> >> On 2010-02-19, Ing. Jan Novotný <novotn...@gmail.com> wrote: >> > 3rd March. >> > >> > 2010/2/19 Clinton Begin <clinton.be...@gmail.com> >> > >> >> When is your workshop? >> >> >> >> On 2010-02-18, Ing. Jan Novotný <novotn...@gmail.com> wrote: >> >> > Thank you guys for sharing your experience. It's pretty good to hear >> >> > that >> >> > combining annotations and XML approach works in practice. >> >> > >> >> > My first thought was, that in case of large systems I wouldn't be >> able >> >> > tu >> >> > guess whether I should look in the Java or XML first when searching >> for >> >> > particular statement definition. Next thought was about portability - >> we >> >> > were forced a couple of times to translate statements in the XML >> >> definitions >> >> > from one DB dialect into another. That is something one must count >> with >> >> when >> >> > writing pure SQL statements. But when they are scattered over these >> two >> >> > kinds of files, I will have to move all statements from interfaces to >> >> > the >> >> > XML and then make a dialect translation. Maybe there could be a way >> of >> >> > extending former interface with annotations override , but this >> doesn't >> >> seem >> >> > much nice to me. What's your view on this? >> >> > >> >> > Btw. the presentation will be more of a workshop and I thought that >> >> > everybody starts just with Maven pom and downloads few libraries from >> >> > the >> >> > public repositories. There the latest one is 3-beta-9. Of course with >> >> some >> >> > effort I could compile new artifact form trunk a distribute it to >> their >> >> > local repositories, you're right. >> >> > >> >> > Jan >> >> > >> >> > 2010/2/19 Nathan Maves <nathan.ma...@gmail.com> >> >> > >> >> >> I completely agree. >> >> >> >> >> >> I too have a project using IB3 and I am really loving mixing the two >> >> >> together. I would give it a try before trying to corner yourself >> into >> >> >> using >> >> >> just one approach. >> >> >> >> >> >> >> >> >> Nathan Maves >> >> >> nathan.ma...@gmail.com >> >> >> >> >> >> >> >> >> >> >> >> On Feb 18, 2010, at 4:09 PM, Clinton Begin wrote: >> >> >> >> >> >> Just curious, why are you limited to 3.0 Beta 9? >> >> >> >> >> >> As for annotations vs. XML, I was worried about splitting between >> the >> >> two >> >> >> at first, and thought that it might be good to choose one approach >> and >> >> >> stick >> >> >> with it. But that would mean you'd have to choose XML, as >> annotations >> >> >> can't >> >> >> compete. That said, I've been working on a project mixing >> annotations >> >> and >> >> >> XML, and I'm very happy with the results. I've found that INSERT, >> >> UPDATE >> >> >> and DELETE statements pretty much always remain as annotations, >> along >> >> with >> >> >> simple SELECT statements. The only things I end up putting in XML >> are >> >> >> very >> >> >> complex queries that include collections or associations. Overall, >> it >> >> >> seems >> >> >> quite clean and easy to follow. I've never been in a situation >> where I >> >> >> was >> >> >> confused about it. >> >> >> >> >> >> Cheers, >> >> >> Clinton >> >> >> >> >> >> 2010/2/18 Ing. Jan Novotný <novotn...@gmail.com> >> >> >> >> >> >>> Hello Clinton, >> >> >>> >> >> >>> many thanks for your answers. They made a lot of things much >> >> >>> clearer >> >> >>> to >> >> >>> me - "the whitepaper" set a lot of expectations in the minds of >> many >> >> >>> people >> >> >>> (including me), so that's why I asked those questions. I am sure >> >> someone >> >> >>> will ask me those questions at the presentation, so I want to be >> >> >>> prepared. >> >> >>> I found some more configuration options in the trunk, but for >> the >> >> >>> presentation I am limited to 3-beta-9 where they didnť work. But >> it's >> >> >>> good >> >> >>> to know, that those issues got answered. >> >> >>> My final question - would you encourage using annotations after >> all? >> >> >>> From the limited experience with iBatis 3 I have, they could be >> used >> >> only >> >> >>> to >> >> >>> simple cases, but they make the code fragmented among annotations >> and >> >> >>> XML. I >> >> >>> can imagine that this could be very confusing in the large scale, >> so >> >> >>> maybe I >> >> >>> should recommend to attendees of the presentation to better stick >> with >> >> >>> good >> >> >>> old XML. What do you think? >> >> >>> >> >> >>> Thanks, >> >> >>> Jan >> >> >>> >> >> >>> Offtopic: >> >> >>> P.S.: you seem very resignated to the Java - does the folks from >> >> >>> Microsoft >> >> >>> got you? :) >> >> >>> >> >> >>> 2010/2/18 Clinton Begin <clinton.be...@gmail.com> >> >> >>> >> >> >>>> Hi Jan, >> >> >>>> >> >> >>>> >> >> >>>> >> expectations come from iBatis 3 Whitepaper >> >> >>>> >> >> >>>> Just to be clear, it wasn't a "white paper" it was a community >> >> >>>> whiteboard >> >> >>>> for brainstorming ideas. So it contained goals and ideas, but >> there >> >> was >> >> >>>> never a commitment to any of them. >> >> >>>> >> >> >>>> >> >> >>>> >> Multilevel Configuration >> >> >>>> >> >> >>>> Ultimately I decided not to implement it this way because it >> became >> >> hard >> >> >>>> to trace where behavior was configured. To fully understand how a >> >> >>>> statement >> >> >>>> might behave or perform, you would have had to look in 3 places. >> I >> >> >>>> wasn't >> >> >>>> satisfied with that, so I made it to be either XML or Annotations >> per >> >> >>>> statement. You can happily mix mappers with annotations or xml >> >> >>>> statements, >> >> >>>> but each statement must use either one or the other. >> >> >>>> >> >> >>>> >> >> >>>> >> to state all properties in order to alter the single one >> >> >>>> >> >> >>>> That's configurable. See the docs under the automappingBehavior >> >> setting >> >> >>>> (I think that's what it's called). >> >> >>>> >> >> >>>> >>annotations >> >> >>>> >> >> >>>> You think it's unpleasant? You should have seen me the day that I >> >> >>>> had >> >> >>>> to >> >> >>>> remove WORKING CODE from my system because Sun changed the >> behavior >> >> >>>> of >> >> >>>> Java >> >> >>>> Annotations between Java 1.5 and 1.6. >> >> >>>> >> >> >>>> In a nutshell, circular references are not supported in the >> >> Annotations >> >> >>>> framework. All of your best hopes and dreams of having something >> >> better >> >> >>>> are >> >> >>>> dashed by this one limitation. There was a workaround in Java >> 1.5, >> >> but >> >> >>>> Sun >> >> >>>> considered it a compiler bug, so they "fixed" the workaround in >> JDK >> >> 1.6. >> >> >>>> If >> >> >>>> you want to see it, you can dig back through a few hundred commits >> >> >>>> and >> >> >>>> see >> >> >>>> where I removed that behavior. >> >> >>>> >> >> >>>> A shame. If this was C# I would have been able to fully realize >> the >> >> >>>> vision of where we wanted to take the annotation (or attributes in >> >> >>>> C#) >> >> >>>> approach. >> >> >>>> >> >> >>>> **>> 3 combinations of annotations and xml >> >> >>>> >> >> >>>> In general, I recommend using annotations for simple things, and >> use >> >> XML >> >> >>>> for anything more complicated. Sorry, but Java annotations are >> just >> >> too >> >> >>>> messy, limited and ugly. There's a million reasons why we had to >> >> scale >> >> >>>> back >> >> >>>> the behavior and limit it to what you see now. If you want to >> >> >>>> understand >> >> >>>> why, I encourage you to try to implement some of your suggestions. >> >> >>>> You'll >> >> >>>> find the same challenges. >> >> >>>> >> >> >>>> >> 4 automatic (generated) SQL >> >> >>>> >> >> >>>> Yes, I completely ditched the idea of generating SQL. It's just a >> >> road >> >> >>>> that I wasn't prepared to take iBATIS down. >> >> >>>> >> >> >>>> >> 5 dynamic sql in annotations >> >> >>>> >> >> >>>> Yes, SelectProvider and the SQL Builder framework are the only way >> >> >>>> (other >> >> >>>> than writing your own). I wasn't about to start putting XML >> embedded >> >> in >> >> >>>> SQL >> >> >>>> embedded in strings embedded in annotations... that's out of hand >> and >> >> >>>> bad >> >> >>>> practice IMHO. >> >> >>>> >> >> >>>> I appreciate your questions, but please realize that everything >> was >> >> >>>> considered. Some things were left out for very good design >> reasons, >> >> >>>> others >> >> >>>> because of limitations in Java and others we might just not have >> had >> >> >>>> a >> >> >>>> chance to implement yet. >> >> >>>> >> >> >>>> Clinton >> >> >>>> >> >> >>>> 2010/2/18 Ing. Jan Novotný <novotn...@gmail.com> >> >> >>>> >> >> >>>>> Hello, >> >> >>>>> >> >> >>>>> >> >> >>>>> I am going to have a presentation about iBatis 3 at Czech JUG. >> I >> >> >>>>> have >> >> >>>>> a 3-year experience with iBatis-2 and now I am doing little >> research >> >> on >> >> >>>>> what's new in upcoming iBatis 3 release. Most of my expectations >> >> >>>>> come >> >> >>>>> from >> >> >>>>> iBatis 3 Whitepaper at the iBatis Confluence site. Now I am >> testing >> >> the >> >> >>>>> new >> >> >>>>> version and there are some things I didn't expect. I will be very >> >> >>>>> pleased if >> >> >>>>> anyone capable could answer me following questions so that I may >> >> >>>>> forward >> >> >>>>> them to the attendees of CZ JUG: >> >> >>>>> >> >> >>>>> * 1) multilevel configuration* >> >> >>>>> Firstly I thought that there would be a chance to override >> >> >>>>> less >> >> >>>>> prioritized level of configuration. Meaning, that if I have SQL >> >> >>>>> represented >> >> >>>>> in an @Select annotation and I create XML statement in mapper >> file >> >> with >> >> >>>>> the >> >> >>>>> same name, this XML declaration will take over the annotation and >> >> will >> >> >>>>> be >> >> >>>>> used instead. Reality is that iBatis will fail to start >> complaining >> >> >>>>> about >> >> >>>>> duplicate declaration. As I discovered, I can use only one or the >> >> other >> >> >>>>> way >> >> >>>>> - I can combine XML file with annotation based Java DAO, but they >> >> must >> >> >>>>> not >> >> >>>>> overlap in the sense of statement declaration. Is that right? Why >> is >> >> >>>>> that >> >> >>>>> done this way? >> >> >>>>> Next I thought there could be some means to explicitly say, >> >> that >> >> >>>>> some parts of the lower configuration level fit for me and >> therefore >> >> >>>>> ease my >> >> >>>>> life a little. Let say I have ResultMap statement in XML >> >> configuration >> >> >>>>> and >> >> >>>>> 95% of its properties is fine by convention, but I need only to >> >> specify >> >> >>>>> more >> >> >>>>> single property or declare association / collection mapping. In >> that >> >> >>>>> case I >> >> >>>>> have to state all properties in order to alter the single one >> that >> >> >>>>> is >> >> >>>>> needed >> >> >>>>> to be extra taken care of (or at least these are my findings from >> >> >>>>> the >> >> >>>>> tests >> >> >>>>> I wrote). What I really want to say is: use convention to all >> >> >>>>> properties >> >> >>>>> except those that I explicitly configure in XML - that is not >> >> possible, >> >> >>>>> is >> >> >>>>> it? >> >> >>>>> >> >> >>>>> * 2) annotations* >> >> >>>>> Another unpleasant surprise was, that I am not able to get >> >> along >> >> >>>>> with annotations to specify <collection> mapping - annotation >> >> >>>>> @Collection is >> >> >>>>> missing. Also @Association is not present - but as I discovered, >> >> >>>>> it's >> >> >>>>> possible to write @Result annotations in the way that associated >> >> object >> >> >>>>> gets >> >> >>>>> mapped. In documentation I found a statement, that annotations in >> >> Java >> >> >>>>> aren't powerfull enough to make some things possible, but I can't >> >> make >> >> >>>>> up >> >> >>>>> why @Collection annotation is not possible to be made. >> >> >>>>> >> >> >>>>> * 3) combination of XML and annotations* >> >> >>>>> I tried combination of XML and annotations (due to lack of >> >> >>>>> @Collection annotation) to specify @Select annotation but specify >> >> >>>>> output as >> >> >>>>> a ResultMap mapping in the XML configuration. But that's not >> >> >>>>> possible >> >> >>>>> too. >> >> >>>>> Mixing configuration from annotations and XML is not possible in >> any >> >> >>>>> way I >> >> >>>>> guess. Ok, but is there any way how to reuse my annotations, to >> get >> >> the >> >> >>>>> same >> >> >>>>> behaviour as reusing ResultMap mapping in different statements of >> >> >>>>> XML >> >> >>>>> configuration?! >> >> >>>>> >> >> >>>>> * 4) automatic SQL implementation* >> >> >>>>> I didn't find any piece of this functionality. May I take >> it, >> >> >>>>> that >> >> >>>>> this was completely discarded? >> >> >>>>> >> >> >>>>> * 5) annotations and dynamic SQL* >> >> >>>>> Finally I didn't find any clue how to use dynamic SQL in >> >> >>>>> annotations. Does that mean that @SelectProviders are the only >> way >> >> how >> >> >>>>> to >> >> >>>>> make dynamic queries by the Java code? >> >> >>>>> >> >> >>>>> Thanks for your time and answers I can use in my presentation >> if >> >> >>>>> anyone asks. Please, don't be offended by my questions, generally >> I >> >> >>>>> think >> >> >>>>> iBatis is a great DAO framework. >> >> >>>>> >> >> >>>>> Cheers Jan >> >> >>>>> >> >> >>>>> -- >> >> >>>>> -------------------------------------------------------------- >> >> >>>>> Ing. Jan Novotný >> >> >>>>> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ >> >> >>>>> http://blog.novoj.net >> >> >>>>> Myšlenky dne otce Fura >> >> >>>>> -------------------------------------------------------------- >> >> >>>>> >> >> >>>> >> >> >>>> >> >> >>> >> >> >>> >> >> >>> -- >> >> >>> -------------------------------------------------------------- >> >> >>> Ing. Jan Novotný >> >> >>> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ >> >> >>> http://blog.novoj.net >> >> >>> Myšlenky dne otce Fura >> >> >>> -------------------------------------------------------------- >> >> >>> >> >> >> >> >> >> >> >> >> >> >> > >> >> > >> >> > -- >> >> > -------------------------------------------------------------- >> >> > Ing. Jan Novotný >> >> > @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ >> >> > http://blog.novoj.net >> >> > Myšlenky dne otce Fura >> >> > -------------------------------------------------------------- >> >> > >> >> >> >> -- >> >> Sent from my mobile device >> >> >> >> --------------------------------------------------------------------- >> >> To unsubscribe, e-mail: user-java-unsubscr...@ibatis.apache.org >> >> For additional commands, e-mail: user-java-h...@ibatis.apache.org >> >> >> >> >> > >> > >> > -- >> > -------------------------------------------------------------- >> > Ing. Jan Novotný >> > @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ >> > http://blog.novoj.net >> > Myšlenky dne otce Fura >> > -------------------------------------------------------------- >> > >> >> -- >> Sent from my mobile device >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: user-java-unsubscr...@ibatis.apache.org >> For additional commands, e-mail: user-java-h...@ibatis.apache.org >> >> > > > -- > -------------------------------------------------------------- > Ing. Jan Novotný > @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ > http://blog.novoj.net > Myšlenky dne otce Fura > -------------------------------------------------------------- >
