Steven,
The database space is tricky. There's the spec. And then there's what
JDBC drivers allow in practice.
According to the actual
Statement JavaDoc:
executeQuery() - Executes the given SQL statement, which returns a single ResultSet object.
executeUpdate() - Executes the given SQL statement, which may be an INSERT, UPDATE, or DELETE statement or an SQL statement that returns nothing, such as an SQL DDL statement.
So while executeQuery() may work on the database you tested with for insert/update/delete, it is not what you are expected to know for the exam. Further, I'd recommend using executeUpdate() for these operations so you have the return code as an integer.