Hi Cíntia,
Derby does not have any builtin support for distributed joins--that is
for running a query which mentions tables in two different databases.
However, you may be able to accomplish what you need to do by using
table functions, a feature that is implemented in the development trunk
and which we expect to expose in Derby 10.4 next year. Table functions
are described in the "Programming Derby-style table functions" section
of the Derby Developer's Guide:
http://db.apache.org/derby/docs/dev/devguide/ Examples of how to use
table functions (including how to write a table function which wraps a
table in another database) can be found in the demo code in the
development trunk at java/demo/vtis--just start with the README file there.
Using table functions, you could fake a distributed join with syntax
like this:
SELECT *
FROM localTable, TABLE( foreignTableFunction() ) foreignTable
WHERE localTable.keyCol = foreignTable.keyCol
Hope this helps,
-Rick
Cíntia wrote:
Hi,
I need do a query in two tables of differents databases, this is
possible? I can do this in java or just using SQL?
Thanks,
Cíntia Nogueira
