The Javadoc for the 1.2 version of JDBCAppender (at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/jdbc/JDBCAppender.html) has a nice big red warning at the top:
WARNING: This version of JDBCAppender is very likely to be completely replaced in the future. Moreoever, it does not log exceptions. Is this warning still accurate? The latest version of 1.2 is almost 2 years old ... is JDBCAppender going to be replaced one day?
