JDBC driver question

[Jonathan Eric Miller]

Hi. I'm new to using Derby. I've used it with limited success so far. 
Currently, I'm receiving the following exception while attempting to insert 
a row in a table using a PreparedStatement which was created using the 
Statement.RETURN_GENERATED_KEYS flag.

Can someone tell me where I can find out what these error codes mean (why o 
why doesn't IBM just print meaningful error messages like every other JDBC 
driver on the face of the planet)? I looked around on IBM's Web site to no 
avail. On a related note, will there be an open source JDBC driver for 
Derby?

com.ibm.db2.jcc.c.SqlException: DB2 SQL error: SQLCODE: -1, SQLSTATE: 23502, 
SQL
ERRMC: ID�23502
       at com.ibm.db2.jcc.c.zc.d(zc.java:1351)
       at com.ibm.db2.jcc.a.eb.l(eb.java:366)
       at com.ibm.db2.jcc.a.eb.a(eb.java:64)
       at com.ibm.db2.jcc.a.r.a(r.java:48)
       at com.ibm.db2.jcc.a.ub.c(ub.java:266)
       at com.ibm.db2.jcc.c.ad.Z(ad.java:1666)
       at com.ibm.db2.jcc.c.ad.d(ad.java:2224)
       at com.ibm.db2.jcc.c.ad.V(ad.java:521)
       at com.ibm.db2.jcc.c.ad.executeUpdate(ad.java:504)

Jon