Thanks for finding this bug, Krzysztof. Derby is using the wrong
classloader to look up optimizer overrides for table functions and this
raises the ClassNotFoundException which you are seeing. I have logged
the following issue to track the problem:
http://issues.apache.org/jira/browse/DERBY-4126
Thanks,
-Rick
Krzysztof N wrote:
Futhermore, I'm able to stop on breakpoint while debugging this table
function and select'ing does not even have a chance to call it, obviously.
Best Regards
Krzysztof N wrote:
Hello,
I'm trying to get basic table function running without much success.
Either error is misleading or I missed some basic point, could you
please advise?
public class DerbyBlobTableFunction {
//this works
public static int returnSth()
{
return 1;
}
//does not work, see error below
public static ResultSet getTSValuesEmpty() throws SQLException
{
List<double[]> results = new ArrayList<double[]>();
results.add(new double[]{1.0,2.0,3.0});
ResultSet rs = new ResultSetTemplate(results);
--//ResultSetTemplate implements ResultSet but same error with Derby
impl of ResultSet
return rs;
}
}
then
CALL SQLJ.install_jar
('/pathto/kn.jar', 'APP.kn', 0); -- OK
CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY
('derby.database.classpath', 'APP.kn'); --OK
CREATE FUNCTION MYFUNC() returns int PARAMETER STYLE JAVA reads
sql data language JAVA EXTERNAL NAME
''gaia.cu7.dal.DerbyBlobTableFunction.returnSth'; --OK
values MYFUNC() ; --OK
returns:
1
CREATE FUNCTION getTSValuesEmpty()
RETURNS TABLE
(
obs double,
val double,
valError double
)
LANGUAGE JAVA
PARAMETER STYLE DERBY_JDBC_RESULT_SET
reads SQL data -- switching to no sql does not change
EXTERNAL NAME ''gaia.cu7.dal.DerbyBlobTableFunction.getTSValuesEmpty'
--OK
then:
select * from table ( getTSValuesEmpty() ) t;
gives:
An error occurred when executing the SQL command:
select * from table ( getTSValuesEmpty() ) t
The exception 'java.lang.ClassNotFoundException:
gaia.cu7.dal.DerbyBlobTableFunction' was thrown while evaluating an
expression. [SQL State=38000, DB Errorcode=20000]
Next: Java exception: 'gaia.cu7.dal.DerbyBlobTableFunction:
java.lang.ClassNotFoundException'. [SQL State=XJ001]
Execution time: 0.04s
1 statement(s) failed.
_but_
values getTSValuesEmpty();
gives:
1
gaia.cu7.dal.resultsettempl...@10fa2e17
MacOS, Derby 10.4.2.0, embedded mode.
Could you please enlighten me what could be wrong? Seems error message
is plain wrong as 'values' returns the reference to resultset, and
regular function from the same class works as well as values call..
Best regards,
Krzysztof
