Random Row

[savagenoob]

I am using MySQL to return a random row but it loops through and I was wondering of a way to not return a row that has already been displayed. Its a quiz program and the user selects the number of questions they want displayed and the code loops through that many rows.

 

$select = "SELECT * FROM pq_crtp_quiz WHERE testname = '$testname' ORDER BY RAND() DESC LIMIT 1";

[Maq]

Your query is only returning 1 row, so we would need to see the surrounding code where it loops.

 

You may be able to just use DISTINCT rather then a loop.  Again, we would need to see some more code.

[Daniel0]

Can't you just set the LIMIT in the query to the number of rows the user asked for?

[savagenoob]

No because the page refreshes each time the user submits the answer to a question. I think I have to store the question numbers already called in a table in the database and cross reference it each page submit. Might work.

[Daniel0]

Then something like this perhaps (assuming id is the primary key):

 

session_start();

if (!isset($_SESSION['selected'] || !$in = join(',', $_SESSION['selected'])) {
$in = null;
}
else {
$in = ' AND id NOT IN (' . $in . ')';
}

$res = mysql_query("SELECT * FROM pq_crtp_quiz WHERE testname = '{$testname}'{$in} ORDER BY RAND() DESC LIMIT 1");

$row = mysql_fetch_assoc($res);

$_SESSION['selected'][] = $row['id'];