Hi @Yu_C
Welcome to KNIME Forum. Take a look at this topic on the Forum. Where @ArjenEX explains how to get the RuleEngine to work. Or see this video on Youtube by @TosinLitics . If you still have problems getting things to work, upload your workflow with some sample data, and I’m sure someone will help you out. And as your a new to KNIME, you may like this https://www.knime.com/knime-self-paced-courses.
Happy KNIMEing
gr. Hans