Karl
All the constraint/ri ui code can a) be extracted out of the DB or b) be
autogenerated from metadata
> Where does referential integrity end and business logic begin anyway?
firstly I make the distinction in the respect that a change in business
rules should not alter your ri, the difference is breaking ri would
result in "what the sh#t is this", breaking business rules results in
"should we be allowing this sh#t"
Its basically the same mismatch that exists between an OO system and a
Relational Database, it all goes away if you accept/assume that a row of
a table is a class instance persisted, the question is should you?
Neven
Karl @ Work wrote:
Neven wrote:
b) Because the DB Server enforces the rules you have to have the UI
guiding the user otherwise its a 'chuck at the db and see
what happens'
UI (ughh). if you do this then you have duplication in business logic
(in the ui and the db) and therefore the inevitability of errors
What about foreign keys and unique indices? Or database constraints? To
push your statement to its logical conclusion, such things could all be
checked at the UI stage and they could be left out of the db entirely.
Personally, I think it's perfectly reasonable to have stored procedures (and
triggers) do similar checks on data validity to ensure that no code slips
ever permit crap into the database, which it seems to me was what Kurt was
advocating. So you might end up duplicating some logic at the front and
back ends, but not to cause errors - to catch them. Just like foreign key,
unique index and other constraints, stored procedures to do referential
checks on data validity are a safety net.
Where does referential integrity end and business logic begin anyway?
Cheers,
Carl
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