On 27 Apr., 02:31, Arne Vajh?j<a...@vajhoej.dk> wrote:
On 26-04-2010 16:14, Robert Klemme wrote:
Btw, did I mention that I believe database independence is a myth? :-)
It is a myth that is seen working everyday in the Java world, that
many Java apps using a good ORM (like Hibernate or one
of the JPA implementation) use the same Java code with different
databases. It is not always that easy. But for all the simple
stuff it works well.
Hm... The question is: how simple is "simple" and where does
"complicated" begin? Just an example, which I would rather place in
the "simple" bucket: assume you want to query for items that have a
field set to null. Considering that Oracle does not index NULL values
and another RDBMS that you want to use does so, you'll likely end up
with a clutch: either you use a different value for NULL which will
allow for uniform ORM code at the cost of a bad design; or you need to
make the ORM tool create different queries (and I do not mean the
difference between "VARCHAR2" and "VARCHAR") for Oracle and the other
RDBMS. You could, of course, also live with the FTS in Oracle but I
doubt you'll have much fun doing this on any reasonably large
database. :-)