1. JDBC Connection & SQL Errors My first roadblock wasn't even logic — it was just getting connected. I kept hitting: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure ** What was going wrong:** Wrong JDBC URL format (missing useSSL=false or timezone parameter caused issues on newer MySQL versions) MySQL service not running Driver JAR not added to the classpath correctly How I fixed it: java String url = "jdbc:mysql://localhost:3306/vo...