Having trouble with echo NULL values & trailing slash?

[computerbarry]

Hi all, in the process of updating and changing my database tables but I'll getting into those other problems later..

Ok so my problem is:

echo "{$row1['dr2']} - <a href=\"gallery1/{$row1['event_id']}/{$row1['venue_id']}/{$row1['date']}\">{$row1['event_id']}{$row1['venue_id']}</a><br>\n "; 

Which outputs below:

example
URL: ../event/venue/2007-09-27 (which works great..)

Full code:

<?php
    require_once('includes/mysql_connect.inc.php');
    $query = "SELECT venue_id, event_id, DATE_FORMAT(date, '%d/%m/%y') AS dr2, date FROM gallery_details ORDER BY date DESC ";
    $res = mysql_query($query);
    while($row1 = mysql_fetch_assoc($res))
    echo "{$row1['dr2']} - <a href=\"gallery1/{$row1['event_id']}/{$row1['venue_id']}/{$row1['date']}\">{$row1['event_id']}{$row1['venue_id']}</a><br>\n ";
    ?>

.. until my 'gallery_details' will have no venue or no event and stays NULL in my table and outputs:

URL: ../event//2007-09-27
or
URL: ..//venue/2007-09-27

how can i work around the trailing slash problem when venue_id or _event_id has no value?

any suggestions?

Thanks

[baileylo]

if(isset($variable)){
echo "/{$variable}";
} 

going to be alot of if statments but it'll work

[computerbarry]

thanks for the quick response baileylo, could you show an example and were to place this in the code?

Thanks

[baileylo]

This is how'd i'd do it.

<?php
    require_once('includes/mysql_connect.inc.php');
    $query = "SELECT venue_id, event_id, DATE_FORMAT(date, '%d/%m/%y') AS dr2, date FROM gallery_details ORDER BY date DESC ";
    $res = mysql_query($query);
    while($row1 = mysql_fetch_assoc($res))
             $Link = "<a href='gallery1/{$row1['event_id']}/";
             if(isset($row1['venue_id']))
                  $Link .= $row1['venue_id'] . '/';
             $Link .= "{$row1['date']}' >";
    echo $row1['dr2'] . $Link . "{$row1['event_id']}{$row1['venue_id']}</a><br>\n ";

    ?>

And i believe that should do it, ad in more issets for other values that could be null.

[computerbarry]

Ok so I've used the code above and now it just stays blank?? it doesn't show the links?

Cheers

[trib4lmaniac]

Ok so I've used the code above and now it just stays blank?? it doesn't show the links?

Cheers

Without looking at the code too much, it looks as if you need braces around the loop.

<?php
require_once('includes/mysql_connect.inc.php');
$query = "SELECT venue_id, event_id, DATE_FORMAT(date, '%d/%m/%y') AS dr2, date FROM gallery_details ORDER BY date DESC ";
$res = mysql_query($query);
while($row1 = mysql_fetch_assoc($res))
{
    $Link = "<a href='gallery1/{$row1['event_id']}/";
    if(isset($row1['venue_id']))
        $Link .= $row1['venue_id'] . '/';
    $Link .= "{$row1['date']}' >";
    echo $row1['dr2'] . $Link . "{$row1['event_id']}{$row1['venue_id']}</a><br>\n ";
}
?>

[computerbarry]

cheers trib4lmaniac, that fixed the problem but just back were i started, it still shows the trail slash:

../venue//2007-09-28 and ..//event/2007-09-28

??

thanks

[AlienDev]

Why not just use:

$url = 'gallery1/ ' . $row1['event_id'] . $row1['venue_id'] . $row1['date'];
// does regex need /'s escaped? i cant remember
$url = preg_replace('~\/\/~', '/', $url);

echo $row1['dr2'] . ' - <a href="' . $url . '">' . $row1['event_id'] . $row1['venue_id'] . '</a><br />'; 

PS: dont use double quotes and {} for variables - it makes it so hard to read and looks stupid.

[logic_earth]

One way to do it

<?php

require_once('includes/mysql_connect.inc.php');

$query = "SELECT venue_id, event_id, DATE_FORMAT(date, '%d/%m/%y') AS dr2, date FROM gallery_details ORDER BY date DESC";
$res = mysql_query($query);

while ($row1 = mysql_fetch_assoc($res)) {
    
    $link = join('/', array_filter(
        array('gallery1', $row1['event_id'], $row1['venue_id'], $row1['date'])
    ));

    $form = '%s - <a href="%s">%s</a><br>';

    printf($form, $row1['dr2'], $link, $row1['event_id'] . $row1['venue_id']);

}

Or

<?php

require_once('includes/mysql_connect.inc.php');

$query = "SELECT venue_id, event_id, DATE_FORMAT(date, '%d/%m/%y') AS dr2, date FROM gallery_details ORDER BY date DESC";
$res = mysql_query($query);

while ($row1 = mysql_fetch_assoc($res)) {

    $link = 'gallery1/' . $row1['event_id'] . '/' . $row1['venue_id'] . '/' . $row1['date'];
    $link = preg_replace('~/{2,}~', '/', $link);
    
    $form = '%s - <a href="%s">%s</a><br>';

    printf($form, $row1['dr2'], $link, $row1['event_id'] . $row1['venue_id']);

}

[computerbarry]

Cheers guys, I've used logic_earth 2nd example, seems to work ok. I tried your example AlienDev works ok but theres no '/' between each variable.

Would it be possible to add a couple of comments on logic_earth 2nd example?

Thanks

UPDATE:

If theres an event and venue together, how could I add @ after the event (event@venue) like so, to the printf and not if it's only venue?

Thanks

[logic_earth]

comments you mean describing whats going on?

<?php

    // Build the link even with null values.
    $link = 'gallery1/' . $row1['event_id'] . '/' . $row1['venue_id'] . '/' . $row1['date'];

    // Clean up the link strip out excess forward slashes (//, ////).
    $link = preg_replace('~/{2,}~', '/', $link);

    // How should it look when we output. %s = string data, Three postions total.
    $form = '%s - <a href="%s">%s</a><br>';

    // Take the format above and process it using the below function inserting
    // the data of our chocie in the postion of our choice.
    printf($form, $row1['dr2'], $link, $row1['event_id'] . $row1['venue_id']);

[computerbarry]

comments you mean describing whats going on?

Yes. Thanks alot logic_earth

Just one last thing:

How could I add @ after the event (event@venue) like so if both columns are present to to the printf output that is? It currently shows eventvenue?

// Take the format above and process it using the below function inserting
    // the data of our chocie in the postion of our choice.
    printf($form, $row1['dr2'], $link, $row1['event_id'] . $row1['venue_id']); 

Thanks again

[logic_earth]

Simple just change $row1['event_id'] . $row1['venue_id']
To $row1['event_id'] . '@' . $row1['venue_id']

Or

// Four postions, added 1 extra (%s-@-%s)
$form = '%s - <a href="%s">%s@%s</a><br>';
printf($form, $row1['dr2'], $link, $row1['event_id'], $row1['venue_id']); 

[computerbarry]

thanks logic_earth. the first example works but I only need it to show when there is an event@venve.

It shows event@venue but it also shows @venue when theres no event, plus if theres just event it shows @event, I only want it to show like I said when event has a venue, making sense?

there second example gave an error:

Warning: printf() [function.printf]: Too few arguments in .../mysite/.. etc

thanks again

[logic_earth]

<?php

require_once('includes/mysql_connect.inc.php');

$query = "SELECT venue_id, event_id, DATE_FORMAT(date, '%d/%m/%y') AS dr2, date FROM gallery_details ORDER BY date DESC";
$res = mysql_query($query);

while ($row1 = mysql_fetch_assoc($res)) {

    // Build the link even with null values.
    $link = 'gallery1/' . $row1['event_id'] . '/' . $row1['venue_id'] . '/' . $row1['date'];

    // Clean up the link strip out excess forward slashes (//, ////).
    $link = preg_replace('~/{2,}~', '/', $link);

    // If both event_id and venue_id are not empty then add @ between them.
    if (!empty($row1['event_id']) && !empty($row1['venue_id'])) {
        $text = $row1['event_id'] . '@' . $row1['venue_id'];
    } else {
        $text = $row1['event_id'] . . $row1['venue_id'];
    }

    // How should it look when we output. %s = string data, Three postions total.
    $form = '%s - <a href="%s">%s</a><br>';

    // Take the format above and process it using the below function inserting
    // the data of our chocie in the postion of our choice.
    printf($form, $row1['dr2'], $link, $text);

}

[computerbarry]

Big thanks

works great now, gave an error at first:

} else {
        $text = $row1['event_id'] . . $row1['venue_id'];
    } 

just deleted .

} else {
        $text = $row1['event_id'] . $row1['venue_id'];
    } 

solved the problem

Thanks again logic_earth

If you get the chance have a look at:
Need help with SELECT & WHERE? its the next step from the above just having a little bit of trouble, cheers