next / previous row ...?

[perik]

Hi!

Ive been trying to paginating my articles. First Ive been trying with this script:

 
		$goin_back = $sub_action - 1;
		$goin_ahead = $sub_action + 1;

	$NEXT = "<a href='content.php?article.$goin_ahead'>next article >></a> ";
	$PREV = "<a href='content.php?article.$goin_back'><< previous article</a> ";

	echo "$PREV";
	echo "$NEXT";

$sub_action is the article_id for example article.4

this works but the problem is that the article_id:s arn't like: 1,2,3,4,5,6,7 ...
some of the id:s are missing so the articles_id:s are more like: 1,3,6,8,11,15 ...

therefor ive been thinking that there should be a way of calling for the next and previous row in the database instead of the previous and next article_id.

How can I do this?

Anyone knows a code, maybe similiar to mine above but selecting the next row instead of next article_id???

Also how can make the next link dissapear when you have reached the last row in the databastable and same thing with previouslink when you reach the first row?

Something like:

if($sub_action < FIRST ROW IN THE TABLE){
$PREV =  "";
}
if($sub_action > LAST ROW IN THE TABLE){
$NEXT =  "";
}

Thanks for your help!

Perd

[laserlight]

Read up your database documentation on SELECT ... LIMIT
e.g.

SELECT * FROM tablename LIMIT 10, 5;

This selects 5 rows from table tablename starting from 10 rows after the first row.
Of course, you would need an ORDER BY clause for "first row" to make sense.

[perik]

i dont know much php

have you got any suggestion of a code that I can use???

thanks for your reply

[Installer]

Here's some q & d code. There are lots of pagination scripts around, maybe working with one can help get you started learning PHP. Use the manual(s). Also, go to this page and click on "pagination".

$max = 1;
$db = mysql_connect('server', 'uname', 'pword');
if (!isset($_GET['i'])) {
    $query = 'SELECT * FROM table';
    $result = mysql_query($query, $db);
    $num_rows = mysql_num_rows($result);
    header('Location: ' . $_SERVER['PHP_SELF'] . '?i=0&t=' . $num_rows);
} else {
    $index = $_GET['i'];
    $total = $_GET['t'];
    $query = 'SELECT * FROM table LIMIT ' . $index . ',' . $max;
    $result = mysql_query($query, $db);
    while ($row = mysql_fetch_array($result)) {
        foreach ($row as $item) {
            echo $item . '<br />';
        }
        echo '<br />';
    }
    if (($index - $max) >= 0) {
        echo '<a href="' . $_SERVER['PHP_SELF'] . 
             '?i=' . ($index - $max) . '&t=' . $total . '">' .
             'Previous</a><br />';
    }
    if (($index + $max) < $total) {
        echo '<a href="' . $_SERVER['PHP_SELF'] . 
             '?i=' . ($index + $max) . '&t=' . $total . '">' .
             'Next</a><br />';
    }
    echo 'Page ' . (($index / $max) + 1) . ' of ' . ceil($total / $max);
}

[stevesweetland]

a simple chunk of code i use for basic pagination....

$limit = 4; // rows per page
if (!isset($row)) $row= 0;

$sql = "SELECT * FROM Table Limit $row,$limit";
$db->query($sql);
$totaldocs = $db->recordcount(); // get record count
while ($db->next_record()){
  // spit out the records here
};

// prev / next links

if (($row - $limit) > 0){
  $var = $row-$limit;
  $back = "<a href=\"events.php?row=$var$extraurl\"><b><< back</b></a>";
};

if ($row != 0 && ($row - $limit) <= 0 && $row != ""){
  $back = "<a href=\"events.php?row=0$extraurl\"><b><< back</b></a>";
};

if (($row + $limit) < $totaldocs){
  $var = $row+$limit;
  $next = "<a href=\"events.php?row=$var$extraurl\"><b>next >></b></a>";
};

print $back.$next;

note my use of database objects ($db->query etc) - you will need to replace these with your chosen method of database access.

worth reading - click here!

for the sake of niceness and possible forum propriety - you might choose to use the php mysql functions, and implement the code like so

$link = mysql_connect("localhost","mysql_user","mysql_password"); // connect
$db = mysql_select_db("mysql_ database",$link) or die(mysql_error()); // select the database

$limit = 4; // rows per page
if (!isset($row)) $row= 0;

$sql = "SELECT * FROM Table Limit $row,$limit";
$result = mysql_db_query($sql,$link) or die(mysql_error()); // do the query
$totalrows = mysql_num_rows($result); // get record count
for ($i = 0; $i < $totalrows; $i++){
  $databasefield = mysql_result($result,$i,"field");
  print "$databasefield<br>"; // spit out the records here
};

// prev / next links

if (($row - $limit) > 0){
  $var = $row-$limit;
  $back = "<a href=\"events.php?row=$var$extraurl\"><b><< back</b></a>";
};

if ($row != 0 && ($row - $limit) <= 0 && $row != ""){
  $back = "<a href=\"events.php?row=0$extraurl\"><b><< back</b></a>";
};

if (($row + $limit) < $totaldocs){
  $var = $row+$limit;
  $next = "<a href=\"events.php?row=$var$extraurl\"><b>next >></b></a>";
};

print $back.$next;