On 05/06/2012 18:45, Dag H. Wanvik wrote:
Looks like a bug to me. The error "XSCH4 Conglomerate could not be
created" isn't being tested for in the Derby tests as far as I can
see. I also searched the bug tracker
(https://issues.apache.org/jira/browse/DERBY) in vain for this
particular error.
Looking in the code where the error is reported in the source code, it
looks like it shouldn't happen. Could you post a JIRA bug report for
this error, please? It you are able to make a stand-alone repro that
will increase your chances of having it fixed.
After trying to boil this down and after much head-scratching, I've
realised that I do the insert using a method in a DB utility class.
There are two methods: dbInsert() and dbUpdate(). The difference is
that doInsert() uses Statement.RETURN_GENERATED_KEYS when creating
the prepared statement, and then calls stat.getGeneratedKeys() after
the insertion.
My problem seems to arise because I used doInsert to execute the insert
even though there isn't a generated key. If I use dbUpdate() instead,
the problem goes away.
My attempt at a standalone repro tries to mimic this behaviour like so:
AUTOCOMMIT OFF;
INSERT INTO resources ...;
INSERT INTO resource_usage ...;
PREPARE p AS ...;
EXECUTE p USING ...;
VALUES IDENTITY_VAL_LOCAL();
COMMIT;
but this works. So I suspect that IDENTITY_VAL_LOCAL is implemented
differently, and the problem is due to Statement.RETURN_GENERATED_KEYS
being used with a statement that doesn't generate a key.
The stack trace I posted earlier began:
java.sql.SQLException: Conglomerate could not be created.
at
org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown
Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
at
org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown
Source)
at
org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown
Source)
at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown
Source)
at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown
Source)
at org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(Unknown
Source)
at
org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeStatement(Unknown
Source)
at
org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeUpdate(Unknown
Source)
at utils.DataManager.dbInsert(DataManager.java:1056)
dbInsert lines 1056/1057 look like this:
stat.executeUpdate();
ResultSet r = stat.getGeneratedKeys();
so the failure happens when the prepared statement is executed, just
before the call to getGeneratedKeys().
Does this suggest a cause for the "Conglomerate could not be created"
error to anyone?
TIA,
--
John English
