Hi Armin, I like that idea! I've just created the page: http://wiki.apache.org/db-ojb/BestPractices
Thomas > -----Original Message----- > From: Armin Waibel [mailto:[EMAIL PROTECTED] > Sent: Tuesday, May 11, 2004 9:59 AM > To: OJB Users List > Subject: Re: OJB practices (best?) > > > Hi John, > > why not start a "OJB best practices" on the OJB wiki > http://wiki.apache.org/db-ojb/ > > in due time we can integrate the best suggestions made on > this page in > OJB documentation. > > regards, > Armin > > McCaffrey, John G. wrote: > > > I would like to know how other teams are using OJB, what > their experiences > > have been, and some of the architecture decisions you have > built around OJB. > > (I know this is not a pure OJB question, but I would like > to help compile a > > list of common architecture approaches to help new people > get started) > > > > Think of it as a "Here's how my team uses OJB" thread > > > > How do most of you organize your data access layer? > > > > Specifically > > Are you building Composite VO/DTOs? (an object that > represents data from > > several tables) > > Do you build a new DAO for every mapped value object (VO)? > > Do you pass these VOs to other layers, or do you adapt them > to a more > > generic object for biz and view purposes? > > Do you use QueryBySQL or ReportQuery often? > > Are you using caching? > > DO you use PB interface? > > How do you manage Transactions? > > > > > > > > Here's how my team uses OJB (RC5) > > We had two basic goals when building our architecture > > 1. isolate View, business, and data access layers so that a > change to one > > wouldn't break the others > > 2. isolate OJB, so that the data access layer could be 'swappable' > > > > Steps we take when building on new functionality (we use PB > interface) > > 1. use (modified) reverseDB to generate VOs and > repository_user.xml for > > tables and views in DB > > 2. modify VOs, and repository_user.xml to reflect our > logical mapping of the > > tables (compositeVOs) > > 3. verify basic CRUD for VO(BaseDAO handles Create, update, insert, > > findByVO, findbyPK for any mapped object) > > (optional) build specific DAO if BaseDAO isn't good enough > > 4. BusinessDelegate objects get handle to DAO through a factory > > 5. BusinessDelegate controls transaction when it needs to > > 6. OJB query and Criteria are wrapped in our QueryVO object > so that biz > > layer doesn't know about OJB > > 7. VOs are adapted to view specific objects and passed to > struts action > > classes (this is to separate the table based VO from the > front-end view) > > > > Misc > > - schema="&schema;" variable is used in > repository_user.xml, so that the > > application can be migrated from test to production > (servlet loads different > > repository.xml in each environment) > > - queryBySQL is used for very complicated SQL (we are > trying to phase this > > out as we learn OJB) > > - When calling DB stored procedures we use OJB to get > sql.connection and the > > appropriate schema > > - We use SequenceManagerNativeImpl to grab DB2 created Identities > > - Created a conversion Boolean2CharYN (for converting a > single char 'Y' or > > 'N' in DB to a boolean > > - We had to create our own PlatformCustDb2Impl because the > identity query(in > > RC5) did work with DB2 7.x > > > > open issues: > > - queryBySQL fails on DB2/websphere 4 when executing the > same query twice > > (we coded a workaround) > > - we have a few 1-1 parent child mappings and we want the > parent to contain > > a child > > - we keep history in our tables, so we often have a date as > a primary key, > > but we don't know the exact date when we do a join, but we > want to join on > > the most current date. this is a problem for 1-1 > > > > > > How are you using OJB? > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
