Dear CSCI 5061 class, it turned out the JDBC demonstration program is fine if I use Oracle JDBC instead of the ODBC driver. It was the first time I used JDBC-ODBC driver (JDBC-ODBC driver should actually be discouraged because it is not pure Java). The problem was in ODBC-Microsoft Access connection. When a program uses Microsoft Access, it locks the entire table, not just the row it needs. It turned out that the Access database we used in the class was left open in my office computer at the time, thus creating weird cursor states. I will post the solution once I have the time to do so.