Michael Maddison
michael at ddisolutions.com.au
Mon Apr 9 21:07:15 CDT 2007
Hmmm, Sounds very close to www.nettiers.com Definitely worth a look for those using VS 2005. cheers Michael M Eeek! How on earth would I do that?? I can explain that we use a data tier that abstracts the actual data structures by building "entity" classes that implement a typeddataset for that data entity and interface classes that define what the data providers will expose for the entity. The entity/typeddataset can address and manipulate a single table or multiple related tables simultaneously. We use an OleDbProvider project that houses the SQL (in XML files) and code classes specific to a related group of tables and their children. The entity classes call into the data provider classes, so the code to do a particular thing (i.e., get the next ID number for a particular table for a particular set of parameters) is in a single location. We build "business rules" into the entity classes that take care of things like returning an exception if a record is being deleted and there are related records that need to be deleted or reassigned. We also use them to cascade changes/deletions/insertions to tables where it can't be done automatically. For instance, when we create a new Well record, the data tier automatically creates and initial wellBore record and doesn't allow the user to delete that wellbore except by deleting the well. Someday, if I ever find the time, I'm going to try modelling this in Access! Any questions?? LOL Charlotte Foust