If it is an IS service, I am pretty confident that if you put a try catch block it should just work fine.
Try block of course will have you database query service. In you catch block put following services:
getLast6Error: pub:flow:getLastError
debugLog:pub:flow:debuglog
These services should catch any error throw during the service…
#webMethods#Flow-and-Java-services#Integration-Server-and-ESB