[slf4j-dev] A problem with Oracle !!!

Dears, I was using Logback.xml configuration during implementing " Loggings " via " SLF4J ", when I faced this problem ... Although I used " DBAppender " before and it was working fine, this time its not at all ... I tried to detect where is the error by the following ways but I could not :- 1 - I added " FileAppender " on the same " backlog.xml ", and it was working fine, while " DBAppender " is not ...2 - I replaced the ORACLE configuration with MYSQL configuration and it worked perfectly !!!! 3 - I replaced the MySql configuration of another working & tested project with Oracle Configuration and it did not work too ... I attached the " backlog.xml " with ORACLE configuration and willing to find help ... Thanks & Regards ...