Using PDO in this script [closed] - php

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Closed 9 years ago.
I'm trying to rewrite this script using PDO:
Get values from the database
mysql_select_db($database_db_FPF, $db_FPF);
$query_rsWorksMenu = "SELECT works.year, GROUP_CONCAT(workstitle.title) as titulos, GROUP_CONCAT(workstitle.id_title) as links FROM works JOIN workstitle ON works.id_year = workstitle.id_year GROUP BY works.year ORDER BY works.year DESC";
$rsWorksMenu = mysql_query($query_rsWorksMenu, $db_FPF) or die(mysql_error());
$row_rsWorksMenu = mysql_fetch_assoc($rsWorksMenu);
Show values
<ul>
<?php do { ?>
<li><span><?php echo $row_rsWorksMenu['year']; ?></span>
<ul>
<?php
$titulos = explode(",", $row_rsWorksMenu['titulos']);
$links = explode(",", $row_rsWorksMenu['links']);
foreach(array_combine($links, $titulos) as $link => $titulo){
?>
<li><span><?php echo $titulo; ?></span></li>
<?php } ?>
</ul>
</li>
<?php }while ($row_rsWorksMenu = mysql_fetch_assoc($rsWorksMenu)); ?>
</ul>
What I got so far:
Get the values from the database:
$stmt2 = $conn->prepare('SELECT works.year, GROUP_CONCAT(workstitle.title) as titulos, GROUP_CONCAT(workstitle.id_title) as links FROM works JOIN workstitle ON works.id_year = workstitle.id_year GROUP BY works.year ORDER BY works.year DESC');
$stmt2->execute();
$result2 = $stmt2->setFetchMode(PDO::FETCH_OBJ);
Show values
<ul>
<?php do { ?>
<li><span><?php echo $result2->year; ?></span>
<ul>
<?php
$titulos = explode(",", $result2->titulos);
$links = explode(",", $result2->links);
foreach(array_combine($links, $titulos) as $link => $titulo){
?>
<li><span><?php echo $titulo; ?></span></li>
<?php } ?>
</ul>
</li>
<?php }while ($row_rsWorksMenu = mysql_fetch_assoc($rsWorksMenu)); ?>
</ul>
The problem is that I don't know what to do with this line:
}while ($row_rsWorksMenu = mysql_fetch_assoc($rsWorksMenu));
UPDATE:
I change my code:
$stmt2 = $conn->prepare('...query...');
$stmt2->execute();
$result2 = $stmt2->fetchAll();
}while ($row_rsWorksMenu = $stmt2->fetchAll());
But nothing happens.
UPDATE 2
I try this code:
<?php do { ?>
<li><span><?php echo $result2->year; ?></span>
<ul>
<?php
$titulos = explode(",", $result2->titulos);
$links = explode(",", $result2->links);
foreach(array_combine($links, $titulos) as $link => $titulo){
?>
<li><span><?php echo $titulo; ?></span></li>
<?php } ?>
</ul>
</li>
<?php }while($result2 = $stmt2->fetch()); ?>
And my DOM show the correct numbers of <li>. But no values. Why?

Answer 1

The easiest way would be something like this:
$sql = 'SELECT name, color, calories FROM fruit ORDER BY name';
foreach ($conn->query($sql) as $row) {
print $row['name'] . "\t";
print $row['color'] . "\t";
print $row['calories'] . "\n";
}
The PDO query method returns a PDOStatement which you can iterate directly.
http://www.php.net/manual/de/pdo.query.php

Answer 2

Drop your while loop completely. You also don't need to prepare a statement separately since your query doesn't use any query parameters.
Do this instead:
// Get all your DB results in one place
$rsWorksMenu = $conn->query($sql)->fetchAll(PDO::FETCH_OBJ);
And later, to display the results:
<?php if ($rsWorksMenu):?>
<ul>
<?php foreach($rsWorksMenu as $r):
$links_titulos = array_combine(
explode(",", $r->titulos),
explode(",", $r->links)
);
?>
<li><span><?=h($r->year)?></span>
<?php if ($links_titulos):?>
<ul>
<?php foreach($links_titulos as $link => $titulo):?>
<li><span><a href="works.php?id=<?=h(urlencode($link))?>"><?=h($titulo)?>a></span></li>
<?php endforeach // $links_titulos?>
</ul>
<?php endif //$links_titulos?>
</li>
<?php endforeach // $rsWorksMenu?>
</ul>
<?php endif // $rsWorksMenu?>
You should change your sql statement also--it will break if any of your links or titles have commas in them. (GROUP_CONCAT is generally a bad idea).
Instead, collect the ungrouped values and group them in a php array yourself, as in the get_worksmenu function below:
<?php
function get_worksmenu(PDO $db) {
$rsWorksMenu = array();
$sql = 'SELECT works.year, workstitle.title AS titulos, workstitle.id_title AS links '
.'FROM works INNER JOIN workstitle USING (id_year) ORDER BY year DESC';
// Could this be a single-table query instead?
// SELECT id_year AS year, title AS titulos, id_title AS links
// FROM workstitle ORDER BY id_year DESC
$rs = $db->query($sql);
$rs->setFetchMode(PDO::FETCH_ASSOC);
foreach ($rs as $r) {
// calculating url here simplifies your display code
// and makes it easy to change urls later
$year = $r['year'];
$r['url'] = '/works.php?id='.urlencode($r['links']);
unset($r['year']);
$result[$year][] = $r;
}
$rs->closeCursor();
return $rsWorksMenu;
}
function h($s) {
// escape a string for html
return htmlspecialchars($s, ENT_QUOTES, 'UTF-8');
}
$rsWorksMenu = get_worksmenu($conn);
<?php if ($rsWorksMenu):?>
<ul>
<?php foreach($rsWorksMenu as $year => $works):?>
<li><span><?=h($year)?></span>
<ul>
<?php foreach($works as $work):?>
<li><span><?=h($work['titulos'])?></span></li>
<?php endforeach //$work?>
</ul>
<?php
</li>
<?php endforeach // $rsWorksMenu?>
</ul>
<?php endif // $rsWorksMenu?>