...
The solution is to stop and restart the database connector. If you are using the tomcat bundle you can do this by: Double click <frevvo-home>\stop-frevvo. Wait until stops. Then Double click <frevvo-home>\start-frevvo
The query returns old results after you update the SQL in configuration.xml
It is very helpful to first test your queries by entering the query URL directly into your web browser and verify that the data resultset returned to your browser as a web page is as you expect. Note however that browsers often cache web pages. If you edit your configuration.xml SQL query and reload/refresh the URL in your browser you may NOT get the updated results due to your browser's caching. Avoid this caching issue by always opening a new browser tab to retest an updated query.