Executes a SQL statement (usually one that doesn’t return a result set). Return value is a ResultSet, to which you can send #rowsAffected (abstract).
Creates a statement object, that can be executed (with parameters, if applicable) repeatedly (abstract).
Returns a Table object corresponding to the given table. Should be overridden by subclasses.
Prepares and executes a SQL statement. Returns the result set or throws an exception on failure (abstract).