Integrating with existing DB

Question

Hi,
I'm investigating Kodo, and how easy it would be to integrate with
existing tables (relational obviously). I didn't find reference to this
in the documentation.
Specifically, I want some tables to have BLOB/CLOB columns, but I don't
want KODO to touch/manage/even think about them. Is this possible? Can
I have control over the field name/column name mapping, and the DB table
name mappings?
I also have a requirement of having a composite primary key for just
about everything. (The first part of the key indicates the company
using the database, and provides extra protection against invalid access
of data in a multi-customer setup). I have read all sorts of nasty
things about having to map my keys to Strings and back again. Is this
going to be an issue/performance issue?
Thanks
Q

Answer 1

I have an existing application that I'm trying to switch from Poet to Kodo.
class A {
     private int a;
class B extends A {
     private int b;
TABLE A (int A_OID, int a);
TABLE B (int B_OID, int a, int b);
Object identifiers (IODs) are globally unique (actually intercorporate
for us).
If one object of A and one object of B exist, then there will be one row
in each table.
Is it possible to map Kodo like that? It appears that attribute a must
be stored in the table A.
Thanks,
Joe Batt
Abe White wrote:
Kodo lets you completely control the mapping process if you want to. Given
that you have an existing schema, you might want to try our reverse
mapping tool, discussed here:
http://www.solarmetric.com/Software/Documentation/latest/docs/ref_guide_pc_reverse.html
That can give you a good starting point. If you already have your
classes, though, then see the metadata section for how to control how
those classes map to tables via metadata extensions:
http://www.solarmetric.com/Software/Documentation/latest/docs/ref_guide_meta.html
The end of that chapter includes examples for mapping some classes to some
tables. If you don't want Kodo to touch some columns, then just don't map
them to any fields.
As far as transferring values to/from strings, Kodo includes the built-in
StringificationMapping (see the "factory" and "externalizer" metadata
extensions), or you can manage that process yourself. Kodo handles
compound primary keys without any problems or performance penalties.