Fname and last name in mysql, error displaying - php

Question

i have a problem in my examination system. In the admin panel, in the results page displays the correct score but the firstname and the last name not. I dont know what to do.
Here is the code:
$result1=executeQuery("select s.nume_student,s.prenume_student,s.stdname,s.stdid, IFNULL((select sum(q.marks) from studentquestion as sq,question as q where q.qnid=sq.qnid and sq.testid=".$_REQUEST['testid']." and sq.stdid=st.stdid and sq.stdanswer=q.correctanswer),0) as om from studenttest as st, student as s where s.stdid=st.stdid and st.testid=".$_REQUEST['testid'].";" );
$result3=executeQuery("SELECT sq.stdid, sq.testid, COUNT(*) AS correctAnswers, SUM(q.marks) AS studentScore,(SELECT SUM(marks) FROM question WHERE testid=".$_REQUEST['testid'].") AS totalScore FROM question q, studentquestion sq WHERE sq.testid=".$_REQUEST['testid']." AND q.testid = sq.testid AND q.qnid = sq.qnid AND sq.answered = 'answered' AND q.correctanswer = sq.stdanswer GROUP BY sq.stdid");
without $result1 doesen't display anything
And here are the tables from database:
question table:
CREATE TABLE IF NOT EXISTS `question` (
`testid` bigint(20) NOT NULL DEFAULT '0',
`qnid` int(11) NOT NULL DEFAULT '0',
`question` varchar(500) DEFAULT NULL,
`optiona` varchar(100) DEFAULT NULL,
`optionb` varchar(100) DEFAULT NULL,
`optionc` varchar(100) DEFAULT NULL,
`optiond` varchar(100) DEFAULT NULL,
`correctanswer` enum('optiona','optionb','optionc','optiond') DEFAULT NULL,
`marks` float(3,2) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
studentquestion table:
CREATE TABLE IF NOT EXISTS `studentquestion` (
`stdid` bigint(20) NOT NULL DEFAULT '0',
`testid` bigint(20) NOT NULL DEFAULT '0',
`qnid` int(11) NOT NULL DEFAULT '0',
`answered` enum('answered','unanswered','review') DEFAULT NULL,
`stdanswer` enum('optiona','optionb','optionc','optiond') DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
student table:
CREATE TABLE IF NOT EXISTS `student` (
`stdid` bigint(20) NOT NULL,
`stdname` varchar(40) DEFAULT NULL,
`stdpassword` varchar(40) DEFAULT NULL,
`emailid` varchar(40) DEFAULT NULL,
`contactno` varchar(20) DEFAULT NULL,
`fname` varchar(40) DEFAULT NULL,
`lname` varchar(40) DEFAULT NULL,
`pincode` varchar(20) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
student test table:
CREATE TABLE IF NOT EXISTS `studenttest` (
`stdid` bigint(20) NOT NULL DEFAULT '0',
`testid` bigint(20) NOT NULL DEFAULT '0',
`starttime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`endtime` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
`correctlyanswered` int(11) DEFAULT NULL,
`status` enum('over','inprogress') DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
and test table:
CREATE TABLE IF NOT EXISTS `test` (
`testid` bigint(20) NOT NULL,
`testname` varchar(30) NOT NULL,
`testdesc` varchar(100) DEFAULT NULL,
`testdate` date DEFAULT NULL,
`testtime` time DEFAULT NULL,
`subid` int(11) DEFAULT NULL,
`testfrom` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`testto` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
`duration` int(11) DEFAULT NULL,
`totalquestions` int(11) DEFAULT NULL,
`attemptedstudents` bigint(20) DEFAULT NULL,
`testcode` varchar(40) NOT NULL,
`tcid` bigint(20) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
I resolved the same problem of here:
How to get sql WHERE statement auto update from localhost link
but i'm stucked here with fname and last name.

Answer 1

If your second query returns the correct student ids, you can just change it to add student names:
SELECT s.lastname, s.firstname, e.*
from
students s join (
... your second query ... ) e
on s.stdid=e.stdid
you can change your join type depends on what you want.

Answer 2

Thanks, but i resolved it like this:
SELECT ***s.fname, s.lname***, sq.stdid, sq.testid, COUNT(*) AS correctAnswers,
SUM(q.marks) AS studentScore,(SELECT SUM(marks) FROM question
WHERE testid=1) AS totalScore
FROM question q, studentquestion sq, ***student s***
WHERE sq.testid=1 AND q.testid = sq.testid
AND q.qnid = sq.qnid AND sq.answered = 'answered' ***and sq.stdid=s.stdid***
AND q.correctanswer = sq.stdanswer GROUP BY sq.stdid