how to create a multi d. array from single query

dmacman1962

Hi All,

I am trying to build a multidimensional array with a single query.

Here is the table.

answer_id --- quiz_id --- q_id --- answer

53 -------------109 -----15 ----Answer 1 - Q1
54 -------------109 -----15 ----Answer 2 - Q1
55 -------------109 -----15---- Answer 3 - Q1
56 -------------109 -----15 ----Answer 4 - Q1
57 -------------109 -----16 ----Answer 1 - Q2
58 -------------109 -----16 ----Answer 2 - Q2
59 -------------109 -----16 ----Answer 3 - Q2
60------------- 109 -----16 ----Answer 4 - Q2
61 -------------109 -----17 ----Answer 1 - Q3
62 -------------109 -----17 ----Answer 2 - Q3
63 -------------109 -----17 ----Answer 3 - Q3
64 -------------109 -----17 ----Answer 4 - Q3
65 -------------109 -----18 ----Answer 1 - Q4
66 -------------109 -----18 ----Answer 2 - Q4
67------------- 109 -----18 ----Answer 3 - Q4
68 -------------109 -----18 ----Answer 4 - Q4

and I am trying to create an answer array like

answer[0].[0] = 53 (qid=15)
answer[0].[1] = 54 (qid=15)
answer[0].[2] = 55 (qid=15)
answer[0].[3] = 56 (qid=15)
answer[1].[0] = 57 (qid=16)
answer[1].[1] = 58 (qid=16)
answer[1].[2] = 59 (qid=16)
answer[1].[3] = 60 (qid=16)
answer[2].[0] = 61 (qid=17)
answer[2].[1] = 62 (qid=17)
answer[2].[2] = 63 (qid=17)
answer[2].[3] = 64 (qid=17)
answer[3].[0] = 65 (qid=18)
answer[3].[1] = 66 (qid=18)
answer[3].[2] = 67 (qid=18)
answer[3].[3] = 68 (qid=18)

I am trying to setup the array so I can loop thru with a simple integer incrementing.

Here is my current, one dimensional array query.

//get the answers
$a = array();
mysql_select_db ($dbname, $conn) or die (mysql_error());
$y=1;
	$query = "SELECT q_id as qid,
	question as q,
	answer_id as aid,
	answer as a,
	caid FROM questions2
	INNER JOIN answers2
	USING(q_id)
	WHERE quiz_id=".$quiz_id."
	ORDER BY q_id, answer_id";
$result = mysql_query($query) or die(mysql_error());
			while ($row = mysql_fetch_array($result)) {
					$answer = $row['a'];
					$a["$y"] = $answer;
					$y++;
					}

Thanks,

Don

dougal85

$result = mysql_query($query) or die(mysql_error());

while ($row = mysql_fetch_array($result)) {
	$answer = $row['a'];
	$a["$y"] = $answer;
	$y++;
					}

ok, if the example you have the question id as the key and the value as the answer?

What other information are you trying to put into the multidimensional array?

dmacman1962

Actually, I'm not. I am trying to get the following.

Array [0] 15(q_id)
------------------Array[0] Answer 1
------------------Array[1] Answer 2
------------------Array[2] Answer 3
------------------Array[3] Answer 4
Array [1] 16 (q_id)
------------------Array[0] Answer 1
------------------Array[1] Answer 2
------------------Array[2] Answer 3
------------------Array[3] Answer 4
etc.

I am trying to get it this way so I can loop thru and get the questions, and answers.

Question 1
-----------Answer 1
-----------Answer 2
-----------Answer 3
-----------Answer 4
Question 2
-----------Answer 1
-----------Answer 2
-----------Answer 3
-----------Answer 4

Does that make sense?

Thanks,
Don

dougal85

$result = mysql_query($query) or die(mysql_error());

while ($row = mysql_fetch_array($result)) {

$answerArray[$row['q_id']][] = $row['answer'];

// if thats not what you want, it might be
// $answerArray[$row['q_id']] = $row['answer'];

}

Roger_Ramjet

Macman, what on earth are you trying to do?

You want to get the questions and answers so that you can display the quiz? You do not need a multi-dimensional array - nor do you need one for anything else you might be trying to do with this thing.

Search these forums for 'loop control' and you will find everything you need to do every possible thing you want. Why do you have to complicate things?

dmacman1962

Hi RR,

Sorry if I seem to be taking the tough road, it seemed like the only one available to me.

I did what you said and I managed to get 3 out of the 4 arrays, (I think) I need to do this.

1) Questions array <== got it
2) Answers array <== did not get
3) Correct Answers array <== got it
4) Students Answers array <== got it

RR Questions array

Array
(
[15] => Here is the 1st question.
[16] => Here is the 2nd question.
[17] => Here is the 3rd question.
[18] => Here is the 4th question.
)

RR's Correct Answers array

Array
(
[15] => 53
[16] => 58
[17] => 63
[18] => 68
)

RR's Students Answers array

Array
(
[15] => 54
[16] => 58
[17] => 62
[18] => 68
)

But the last one, answers array, I think I need to get this...

Array
(
[15] => Answer 1 - Q1
[15] => Answer 2 - Q1
[15] => Answer 3 - Q1
[15] => Answer 4 - Q1
[16] => Answer 1 - Q2
[16] => Answer 2 - Q2
[16] => Answer 3 - Q2
[16] => Answer 4 - Q2
and so on... But I thought I would need to nest these as a multidimensional array using the answer_id's???
)

The answer_id is unique for each, and that is where I am confused.

Am I simplifying this yet? I believe I am going down the route your trying to lead me.

Thanks for your help and patience, I will get this 'eventually.' 🙂

Don

dmacman1962

OK, I know I am close, but my code to test the students answer against the correct one is causing an error.

//Get the first questions ID
mysql_select_db($dbname, $conn) or die (mysql_error());
	$query = "SELECT MIN(q_id)
	FROM questions2
	WHERE quiz_id='".$quiz_id."'";
		$result = mysql_query($query) or die(mysql_error());
		$row = mysql_fetch_array($result) or die(mysql_error());
		$first = $row['MIN(q_id)'];


$t=1;
$aa=53;	//I hard-coded this, I will add the query to look this up later.
$z=$first;		
foreach($que as $key => $value) {
	echo $t.') '.$que[$z].'<br />';
		for($i=1; $i<=4; $i++) {
		  echo $answer[$aa].' '.key($answer).' == '.$sanswer[$z];
		if(($correct[$z]==$sanswer[$z])&&(key($answer)==$sanswer($z))) {
    echo ' <---You got this one right!<br />';
    } else {
   echo '<br />';
	}
         next($answer);
         $aa++;		
         $qq++;
		}
$z++;
$t++;
}

It goes thru the first question (which the student answered wrong) without an error, but gives me this error...

Fatal error: Function name must be a string in Path\forms\quiz\get_my_results3.php on line 148

When it tries to compare the answers for the next question (which the student got right)??

Where is my coding mistake?

Thanks a bunch,
Don