totally stuck

[kzn]

Hi

I am trying to make a multi choice quiz. I aim to randomly select 5 questions from a database of 100 questions. Two are true false, one will have more than one answer, the other two will have one answer.


// select two questions from database that are true / false
$query = "select row_id from questions where multi_answer = 'b' order by rand() limit 2";
$result = mysql_query($query);

while($boolean = mysql_fetch_array($result,MYSQL_ASSOC)){

$quiz[] = $boolean['row_id'];
};

// select two question from database that will have more than one answer
$query = "select row_id from questions where multi_answer = 'y' order by rand() limit 1";
$result = mysql_query($query);

while($multi = mysql_fetch_array($result,MYSQL_ASSOC)){

$quiz[] = $multi['row_id'];
};

// select two questions from database that can have only one answer
$query = "select row_id from questions where multi_answer = 'n' order by rand() limit 2";
$result = mysql_query($query);

while($normal = mysql_fetch_array($result,MYSQL_ASSOC)){

$quiz[] = $normal['row_id'];
};

and I need to work this somehow into the below code. so that it uses the random set of numbers that i know will be made up of the right type of questions. Maybe I have attacked this from totally the wrong angle. Please let me know.

$display = 1;

if(isset($_GET['np'])) {
$num_pages = $_GET['np'];
} else {
$num_pages = 5;
}

// determine where in the database to start returning results
if(isset($_GET['s'])) {
$start = $_GET['s'];
} else {
$start = 0;
}


$query = "select row_id, question from questions limit $start, $display";
$result = mysql_query($query);



while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
echo "No.".$row['row_id']." ".$row['question']."<br />";

$query2 = 'select answer from x_answers where question_id ='.$row['row_id'];
$result2 = mysql_query($query2);

while($row2 = mysql_fetch_array($result2, MYSQL_ASSOC)) {
echo "Answer ".$row2['answer']."<br />";
}

}


################################################################################################################################

// make the links to the other pages
if($num_pages > 1) {
echo '<br /><p>';

// determine what page the script is on
$current_page = ($start/$display) + 1;

// if its not the first page, make a previous button
if($current_page != 1) {
echo '<a href="quiz.php?s='.($start - $display).'&np='.$num_pages.'">Previous</a>&nbsp;&nbsp;';
}

// make all the numbered pages
for($i=1; $i <= $num_pages; $i++) {
if($i != $current_page) {
echo '<a href="quiz.php?s='.(($display * ($i -1))).'&np='.$num_pages.'">'.$i.'</a>&nbsp;&nbsp;';
} else {
echo $i.' ';
}
}

// if its not the last page make a next button
if($current_page != $num_pages) {
echo '<a href="quiz.php?s='.($start + $display).'&np='.$num_pages.'">Next</a>';
}
}


I hope this makes sense. All I need is create a multi choice quiz. It must pull 5 random questions from the database. (made up of two true/false, one multi answer,and two single answer)

each of the possible answers is also put in a random order.

Any help would be much appreciated.

Thank you

 

[darrellblackhawk]

kzn,

This may get you started.

I apologize if there are errors, omissions or bugs.

You'll need to add error detection/mitigation yourself.

Darrell

<?php
// NOTE: (i/o) in front of a function argument means
//             that argument is passed by reference
// totally stuck: [URL unfurl="true"]http://www.tek-tips.com/viewthread.cfm?qid=1441326&page=1[/URL]

$nQuesCnt = 5; // number of questions
$aQuesArray = array(); // array of questions
$aAnsArray = array(); // array of answers

getQandA_ABS($aQuesArray, $aAnsArray, $nQuesCnt);
/* Note:
   Arrays: $aQuesArray and $aAnsArray will have these structures upon return from getQandA_ABS():
	 $aQuesArray[x][0] = 'ans_type' - possible values: 1=Y/N, 2=Multi-answer, 3=Single-answer
	 $aQuesArray[x][1] = 'question' - The question
	 
	 $aAnsArray[x][0] = 'answer' - [x][0] = first answer of multi-answer question
	      ...
	 $aAnsArray[x][y] = 'answer' - [x][y] = last answer of multi-answer question
*/



/************************************************************ 
*
*  This is where your output goes. I'll leave the rest to you... 
*
*************************************************************/




/** Function: getQandA_ABS :: Database abstraction tier
 *	Purpose:  Get the Question and answers - 
 *	Pass:     (i/o) $aQuesArray - The questions array
 *            (i/o) $aAnsArray - The answers array
 *            (i) $nQuesCnt - The number of question/answer pairs
 *	Caller:   ** Main Program **
 *	Calls:    getQandA_DBA()
 *	Return:   ** You should return something - I'll let you work that out. **
 */
function getQandA_ABS(&$aQuesArray, &$aAnsArray, $nQuesCnt) {
	// define and initialize random question placement array
	$aRndPlaceArray = array();
	for ( $i = 0; $i < $nQuesCnt; $i++ ) { 
		$aRndPlaceArray[$i] = false;
	}
	
	seedPlacementArray($aRndPlaceArray, $nQuesCnt);
	getQandA_DBA($aQuesArray, $aAnsArray, $aRndPlaceArray, $nQuesCnt);
}


/** Function: getQandA_DBA :: Database access tier
 *	Purpose:  Query the database and load both the questions and answers array
 *	Pass:     (i/o) $aQuesArray - The questions array
 *            (i/o) $aAnsArray - The answers array
 *            (i) $aRndPlaceArray - The random question/answer placement array
 *            (i) $nQuesCnt - The number of question/answer pairs
 *	Caller:   getQandA_ABS()
 *	Calls:    getConnection()
 *	Return:   ** You should return something - I'll let you work that out. **
 *	Note:     By sending $nQuesCnt, you can work out an algorithm that
 *            will determine a random number of questions to return
 *            of the different question types
 */
function getQandA_DBA(&$aQuesArray, &$aAnsArray, $aRndPlaceArray, $nQuesCnt) {
	
	$rDbc = getConnection(); // Whatever your connection is...
	
	// Queries
	
	// select 2 T/F questions
	$cSQL1 =
		'select 1 as ans_type, a.row_id, a.question, b.answer '
		.'from questions a  '
		.'where a.multi_answer = "b" '
		.'join x_answers b on b.question_id = a.row_id '
		.'order by a.rand() limit 2';

	// select 1 multi-answer question
	$cSQL2 =
		'select 2 as ans_type, a.row_id, a.question, b.answer '
		.'from questions a  '
		.'where a.multi_answer = "y" '
		.'join x_answers b on b.question_id = a.row_id '
		.'order by a.rand() limit 1';

	// select 2 single-answer questions 
	// I assume you'll get mulitple rows based on the
	// row_id in the x_answers table mapping to the 
	// questions table. We'll compensate for this below.
	$cSQL3 = 
		'select 3 as ans_type, a.row_id, a.question, b.answer '
		.'from questions a  '
		.'where a.multi_answer = "n" '
		.'join x_answers b on b.question_id = a.row_id '
		.'order by a.rand() limit 2';
	
	// Do the queries
	$rRS1 = @mysql_query($cSQL1,$rDbc);
	$rRS2 = @mysql_query($cSQL2,$rDbc);
	$rRS3 = @mysql_query($cSQL3,$rDbc);
	
	// Load the Q & A arrays using the random placement array
	$nIndex = 0;
	
	// T/F questions
	while( $rROW = @mysql_fetch_array($rRS1, MYSQL_ASSOC) ) {
		$aQuesArray[$aRndPlaceArray[$nIndex]][0] = $rROW['ans_type'];
		$aQuesArray[$aRndPlaceArray[$nIndex]][1] = $rROW['question'];
		$aAnsArray[$aRndPlaceArray[$nIndex]][0] = $rROW['answer'];
		$nIndex++;
	}

	// multi-answer question
	// This will only allow for 1 multi-answer question
	// to allow for more, you'll need to modify
	$b1stAnswer = true;
	$nAnsCnt = 0;
	while( $rROW = @mysql_fetch_array($rRS2, MYSQL_ASSOC ) ) {
		if($b1stAnswer) {
			$aQuesArray[$aRndPlaceArray[$nIndex]][0] = $rROW['ans_type'];
			$aQuesArray[$aRndPlaceArray[$nIndex]][1] = $rROW['question'];
			$b1stAnswer = false;
			$nIndex++;
		}
		$aAnsArray[$aRndPlaceArray[$nIndex]][$nAnsCnt] = $rROW['answer'];
		$nAnsCnt++;
	}

	// single-answer questions
	while( $rROW = @mysql_fetch_array($rRS3, MYSQL_ASSOC) ) {
		$aQuesArray[$aRndPlaceArray[$nIndex]][0] = $rROW['ans_type'];
		$aQuesArray[$aRndPlaceArray[$nIndex]][1] = $rROW['question'];
		$aAnsArray[$aRndPlaceArray[$nIndex]][0] = $rROW['answer'];
		$nIndex++;
	}
	
	closeConnection($rDbc);
}



/*** These two function allow for better flexibility later on... ***/
function getConnection() {
	// Your database connection goes here...
	// separating connection management allows you to start a connection pooling function...
	return $rDbc;
}
function closeConnection($rDbc) {
  // just close it or return to connection pool
	$didItClose =	@mysql_close($rDbc);
	return $didItClose;
}



/** Function: seedPlacementArray
 *	Purpose:  Seed the random question/answer placement array pointers
 *	Pass:     (i/o) $aRndPlaceArray - The randdom q/a placement array
 *						(i) $nQuesCnt - The number of question/answer pairs
 *	Caller:   ** Main program **
 *	Calls:    getConnection()
 *	Return:   ** You should return something - I'll let you work that out. **
 *	Note:    	By sending $nQuesCnt, you can work out an algorithm that
 *						will determine a random number of questions to return
 *						of the different question types
 */
function seedPlacementArray(&$aRndPlaceArray, $nQuesCnt) {
	while ( true ) { 
		for ( $i=0; $i < $nQuesCnt; $i++ ) {
			$nIndex = rand(0, $nQuesCnt-1);
			if ( !$aRndPlaceArray[$i] && isIndexFree($aRndPlaceArray, $nIndex) ) {
				$aRndPlaceArray[$i] = $nIndex;
			}
		}
		if ( getPlaceArrayCount($aRndPlaceArray) == $nQuesCnt ) { // have we loaded all question placements?
			break;
		}
	}
}


/** Function: isIndexFree
 *	Purpose:  Determine if a particular value is currently in the random placement array
 *	Pass:     (i/o) $aRndPlaceArray - The randdom q/a placement array
 *						(i) $nIndex - The value to test for
 *	Caller:   seedPlacementArray()
 *	Calls:    none
 *	Return:   (o) $bIndexFree - boolean - True := value isn't in the array
 */
function isIndexFree($aRndPlaceArray, $nIndex) {
	$bIndexFree = true;
	for ( $i=0; $i < count($aRndPlaceArray); $i++ ) {
		if ( $aRndPlaceArray[$i] === $nIndex ) {
			$bIndexFree = false;
			break;
		}
	}
	return $bIndexFree;
}


/** Function: getPlaceArrayCount
 *	Purpose:  Return count of array positions that have been filled
 *	Pass:     (i/o) $aRndPlaceArray - The randdom q/a placement array
 *	Caller:   seedPlacementArray()
 *	Calls:    none
 *	Return:   (o) $nCnt - numeric 
 */
function getPlaceArrayCount($aRndPlaceArray) {
	$nCnt = 0;
	for ( $i = 0; $i < count($aRndPlaceArray); $i++ ) {
		if ( $aRndPlaceArray[$i] !== false ) {
			$nCnt++;
		}
	}
	return $nCnt;
}
?>