MySQL

CREATE TABLE IF NOT EXISTS `student` (
  `sid` varchar(30) NOT NULL,
  `fname` varchar(40) NOT NULL,
  `lname` varchar(40) NOT NULL,
  `gradeid` int(2) NOT NULL,
  `termid` int(3) NOT NULL,
  PRIMARY KEY (`sid`),
  KEY `termid` (`termid`)
) ENGINE=MyISAM ;
 
CREATE TABLE IF NOT EXISTS `s_lessons` (
  `lid` int(5) NOT NULL,
  `sid` varchar(15) NOT NULL,
  `termid` int(3) NOT NULL,
  `gradeid` int(11) NOT NULL,
  PRIMARY KEY (`lid`,`sid`,`termid`),
    ) ENGINE=MyISAM ;

SELECT student.sid, student.fname, student.lname
FROM student 
WHERE student.sid NOT IN (SELECT s_lessons.sid 
                                                          FROM s_lessons
                                                          WHERE s_lessons.termid= 900 )

Bernhard Hiller wrote:

you should also configure the MySQL server to allow connections from other computers