Randomly generating data.

pythas

I'm trying to generate a number of questions randomly using PHP and getting the questions from MySql database.
Can anyone help with this please. Thanks.

LordShryku

What have you done so far? Where are you stuck?

BDKR

It sounds to me like what you are really doing is storing a number of questions in MySQL and you would like to pull any one of those out randomly. Is this correct?

If so, consider that it's no big deal to get a count of how many questions are in the db. Once you know that, generate a random number (up to the same number
of questions in the database) then query the db.

Cake! 🙂

Cheers,
BDKR

LordShryku

Or just order by rand() in you sql.

pythas

Originally posted by LordShryku
What have you done so far? Where are you stuck?

I can pull the questions and possible answers out of the db sequentially, but what I want to do is puling 10 questions out randomly out of about 200.

pythas

Originally posted by BDKR
It sounds to me like what you are really doing is storing a number of questions in MySQL and you would like to pull any one of those out randomly. Is this correct?

If so, consider that it's no big deal to get a count of how many questions are in the db. Once you know that, generate a random number (up to the same number
of questions in the database) then query the db.

Cake! 🙂

Cheers,
BDKR

Thanks a lot for the tip. You're quite right about what I wanted to do, but I'm still a beginner in PHP. How do I generate the random numbers, and then query the db. I have about 200 questions.
Many thanks.

rheroux

Here's a function I just wrote that will generate random numbers for you based on the number of questions wanted, the minimum random number wanted and the maximum random number wanted.

<?php

function rand_question($num_questions,$min_num,$max_num)
{

$rand_check = array();

for($i = 0; $i < $num_questions; $i++)
{

$x = rand($min_num,$max_num); // Generate the random number

if(in_array($x,$rand_check)) // So we don't get duplicates
{

$i = $i - 1; // Return $i to it's previous state during this iteration

}

else
{

$rand_check[] = $x; // Pop $x onto the array

}

}

return $rand_check;

}

?>

Although it may be inefficent to use, you could use a for loop afterwards to do your queries for you. As long as your questions in your database have an auto incremented ID field of some sort, then this should work:

$blah = rand_question(10,0,200);

for($i = 0; $i < count($blah); $i++)
{

$sql = "SELECT question FROM table WHERE id = ".$blah[$i]."";

$result = mysql_query($sql) or die ("Could not execute query :".mysql_error());

$row = mysql_fetch_object($result);

echo "Question #".$i.": ".$row->question."<br>";

}

pythas

Do I need the array if I'm getting the data from a database?

Also if I want a page refreshed after each question (ie after answering one question, it refreshes to display the second question on a button click), how do I go about it?

Thanks for your help.

pythas

HEEELLLLLLLLLLLLLLLLLPPPPPPPPPPPPPP!!!!!

pythas

NEED HELP PLEEAAAAAAAAAAAAASSSSSSSEEEEE! CAN SOMEBODY PLEASE HELP....

BDKR

Have you generated any code for this? Let's see some of it. We can help, but many of us won't write it for you.

Cheers,
BDKR

pythas

THIS IS MY CODE SO FAR...ANY HELP PLEASE.....

<?php require_once('Connections/myConn.php'); ?>
<?php
$currentPage = $_SERVER["PHP_SELF"];

$maxRows_rsQuestion = 1;
$pageNum_rsQuestion = 0;
if (isset($GET['pageNum_rsQuestion'])) {
$pageNum_rsQuestion = $GET['pageNum_rsQuestion'];
}
$startRow_rsQuestion = $pageNum_rsQuestion * $maxRows_rsQuestion;

mysql_select_db($database_myConn, $myConn);
$query_rsQuestion = "SELECT * FROM quest_tbl";
$query_limit_rsQuestion = sprintf("%s LIMIT %d, %d", $query_rsQuestion, $startRow_rsQuestion, $maxRows_rsQuestion);
$rsQuestion = mysql_query($query_limit_rsQuestion, $myConn) or die(mysql_error());
$row_rsQuestion = mysql_fetch_assoc($rsQuestion);

if (isset($GET['totalRows_rsQuestion'])) {
$totalRows_rsQuestion = $GET['totalRows_rsQuestion'];
} else {
$all_rsQuestion = mysql_query($query_rsQuestion);
$totalRows_rsQuestion = mysql_num_rows($all_rsQuestion);
}
$totalPages_rsQuestion = ceil($totalRows_rsQuestion/$maxRows_rsQuestion)-1;

$queryString_rsQuestion = "";
if (!empty($SERVER['QUERY_STRING'])) {
$params = explode("&", $SERVER['QUERY_STRING']);
$newParams = array();
foreach ($params as $param) {
if (stristr($param, "pageNum_rsQuestion") == false &&
stristr($param, "totalRows_rsQuestion") == false) {
array_push($newParams, $param);
}
}
if (count($newParams) != 0) {
$queryString_rsQuestion = "&" . htmlentities(implode("&", $newParams));
}
}
$queryString_rsQuestion = sprintf("&totalRows_rsQuestion=%d%s", $totalRows_rsQuestion, $queryString_rsQuestion);

//}
?>
<html>
<head>
<title>Oluseyi's Quiz Page</title>
<style type="text/css">

</style></head>

<body>
<form action="<?php printf("%s?pageNum_rsQuestion=%d%s", $currentPage, min($totalPages_rsQuestion, $pageNum_rsQuestion + 1), $queryString_rsQuestion); ?>" method="post" name="quesForm" id="quesForm">
<?php
do {

if ($pageNum_rsQuestion <= 10 ) {
?>
<table width="738" border="1" cellpadding="5" cellspacing="5" bgcolor="#996600">
<caption align ="left">
<strong> Question
</strong>
</caption>
<tr>
<th colspan="4" scope="col"><div align="left"><?php echo $row_rsQuestion['ques_id']; ?>: <?php echo $row_rsQuestion['questions']; ?></div></th>
</tr>
<tr>
<td colspan="4"> </td>
</tr>
<tr>
<td>A
<input name="radiobutton" type="radio" value="radiobutton">
<?php echo $row_rsQuestion['possible1']; ?></td>
<td>B
<input name="radiobutton" type="radio" value="radiobutton">
<?php echo $row_rsQuestion['possible2']; ?></td>
<td>C
<input name="radiobutton" type="radio" value="radiobutton">
<?php echo $row_rsQuestion['possible3']; ?></td>
<td>D
<input name="radiobutton" type="radio" value="radiobutton">
<?php echo $row_rsQuestion['possible4']; ?></td>
</tr>
<tr>
<td colspan="4"><div align="center">
<input type="submit" name="Submit" value="Submit">
<a href="<?php printf("%s?pageNum_rsQuestion=%d%s", $currentPage, min($totalPages_rsQuestion, $pageNum_rsQuestion + 1), $queryString_rsQuestion); ?>"></a> </div></td>
</tr>
</table>

<?php } ?>
<?php } while ($row_rsQuestion = mysql_fetch_assoc($rsQuestion)) ?>
<p> </p>
<p> </p>
</form>
</body>
</html>
<?php
mysql_free_result($rsQuestion);
?>

BDKR

Did you write this or get it from somewhere else?

Whatever the case, it's dealing with something other than just randomly pulling quiz questions out of a database. A quick look suggests that there is a lot of result set pagination going on here as well. As a matter of fact, there is nothing in there that's dealing with getting random questions out of the db.

As it is, I don't believe you wrote this. That said, here is an algorithm that will help you. Besides, do you want to learn how to code?

1) connect to the database (if not allready).

2) Find out how many questions you have in the table.

3) Select one of those at random.

4) Display it on the page.

If you take each one of those at a time, I'm sure you will be able to find all the info you need in the manuals or through various tutorials on google.

If we write this for you, you don't learn anything. Then you become a liability to yourself and a burden to the rest of us.

So dive in....

pythas

Most of the code was generated by dreamweaver MX, but I did a bit of hand coding as well, to manipulate it.

BDKR

Looking at this again, do you want to also go from page to page? If that's the case, then I misunderstood and you may be a lot closer than I thought.

If so, LordShryku is correct. order by rand() sounds like it would be the ticket in this case.

Sorry for the any mis-understanding. :-(

Cheers,
BDKR

pythas

IT IS REFRESHING THE PAGE AS I WANTED IT TO DO ie going to the next question. MY PROBLEM AT THE MO IS RANDOMLY GENERATING THE QUESTIONs.
I TRIED USING THIS QUERY:
SELECT * FROM QUESTION ORDER BY RAND() LIMIT 1
BUT I GOT AN ERROR WITH THE QUERY.
THAKS FOR YOUR HELP.

datona

Dusting this one off and asking......

How can one using php and Mysql implement pagination with: ORDER BY rand()

Any help would be greatly appreciated!

bradgrafelman

"Dusting this one off" indeed... heh.

I would take a look at this thread (specifically, this post by mrhappiness).

Though is code is a bit messy, I believe his thought process is ideal.

datona

Yes I did try THIS CODE but for the life of me (well a good 8 hours anyways) I have not been able to get it to work.

datona

Anyone???
I am truly going crazy here attempting to get this to work.