Question

Having some issues, basically I have a random image gallery.

This is the code for the random thumbnails:

<?php
include('../../connect.php');
$result = mysql_query("SELECT *
                       FROM picture AS r1
                       JOIN
                       (
                          SELECT ROUND(RAND() * (SELECT MAX(id)
                                                 FROM picture) ) AS id
                       ) AS r2 
                       WHERE r1.id >= r2.id 
                          AND public_approved=1
                       ORDER BY r1.id ASC 
                       LIMIT 4;")
or die(mysql_error());

while($row = mysql_fetch_array( $result ))  
{
echo "<div style='float:left; margin:2px;' >";
echo '<a href="pictures.php?id=' . $row['id'] .'"><img src="../../files/small/thumb0_'. $row['file_name'] . '.' . $row['file_extension'] . '" border="0"></br>';
echo "</div>";
}
?>

When one of the thumbnails is clicked the page reloads and uses the following command to load the main content:

<?php
include('../../connect.php');

$passed_id = $_GET['id']; 

$result1 = mysql_query("SELECT * FROM picture where id='$passed_id' ")
  or die(mysql_error());

while($row = mysql_fetch_array( $result1 ))     
{?>

This continues on through a table displaying the larger image and title and so on.

I’m experiencing two problems:

1 – Even though I specify 4 in the limit, sometimes only 1 2 or 3 thumbs are displayed.

2 – Sometimes when I click on a thumbnail the wrong id is used, i.e. thumbnail id 2 but firing id 8.

Answer 1

Suppose X is the number of images you want to display, you should really take [MAX(id) – X] as the RAND() multiplier. This way the result set will have enough results.

Second problem seems simple, someone will probably post a good answer, but keep in mind it’s usually a column/parameter confusion in your php/html code.

Good luck!