CODEWITHSUNDEEP
phpmysql
themeparkfocus
themeparkfocus

Reputation: 187

PHP if query not behaving correctly

I'm using an if statement in PHP whereby if a query is empty it doesn't run the PHP effectivily hiding that part of the web page. This is the if statement I'm using

if(!empty($result4)){

}

It works fine elsewhere when used to hide individual empty rows from a whole result but when run for a whole query it doesn't work.

This is the whole php code everything below if(!empty($result4)){ should not happen if query is empty, but it is.

<?php 
if(!empty($result4)){


printf('<h2>%s News' . PHP_EOL, $row['name']);



$sLastStory = '';
foreach ($result4 AS $row4)
{
    $sStory = $row4['headline'] . $row4['story'];
    if (strcasecmp($sStory, $sLastStory) != 0)
    {
        if (!empty($sLastStory))
        {

        }
        $sLastStory = $sStory;


        printf('<h3>%s</h3>' . PHP_EOL, $row4['headline']);

        printf('<h4>%s</h4>' . PHP_EOL, $row4['Displaydate']);

        printf('<p>%s</p>' . PHP_EOL, $row4['story']);
    }

if(!empty($row4['url'])){   
printf('
<a href="/images/%s%s.jpg" rel="lightbox[%s]" title="%s - Credit - %s" >
<img src="/images/%s%s-thumb.jpg" style="max-height: 230px; max-width: 230px" alt="%s"/></a>' . PHP_EOL, $row4

['url'], $row4['alt'], $row4['headline'],  $row4['description'],$row4['credit'], $row4['url'], $row4['alt'], 

$row4['alt'] );
}

}

printf('

<br>

<hr>
<a class="bloglink" href="parknews.php?park_id=%s">See all %s news</a></li>' . PHP_EOL, $park_id, $row

['name']);

}
?>

Any ideas how to make it work?

If it helps this is the MySQL query:

$park_id = $_GET['park_id'];
$query4= 'SELECT headline, story, DATE_FORMAT(date, "%d-%M-%Y") AS Displaydate, url, alt, description, credit
FROM tpf_news 
LEFT JOIN tpf_images ON tpf_news.news_id = tpf_images.news_id 
Where tpf_news.park_id = ' .  $park_id .' ORDER BY date DESC';
$result4 = $pdo->query($query4);

Thanks

Upvotes: 0

Views: 137

Answers (6)

George Cummins
George Cummins

Reputation: 28906

If the query succeeded, PDO::query() will return a PDOStatement even if no rows were selected. Since $result4 contains a PDOStatement, it is not empty.

A better way to check the number of returned rows is PDOStatement::rowcount:

if( $result4->rowCount() ){

Upvotes: 3

Marcos Tavares
Marcos Tavares

Reputation: 113

Try this

if (is_array($result4) && sizeof($result4)>0) {
    // your code here!
}

or 

$query4 = 'SELECT headline, story, DATE_FORMAT(date, "%d-%M-%Y") '
    . ' AS Displaydate, url, alt, description, credit '
    . ' FROM tpf_news '
    . ' LEFT JOIN tpf_images '
    . ' ON tpf_news.news_id = tpf_images.news_id '
    . ' Where tpf_news.park_id = ? '
    . 'ORDER BY date DESC';

$st = $pdo->prepare($query4);

// The following code can be placed in a loop

$st->execute(array($_GET['park_id']));

if ($st->rowCount()>0) {
    $aResult = $st->fetch();
    // your code

}

Marcos

Upvotes: 0

Fabio
Fabio

Reputation: 23480

A result of a query will never be empty, also if there are no rows matched. It could be either null or have anything else, so your condition if(!empty($result4)) will be never satisfied. You should check for num_rows returned instead

if($result4->rowCount() > 0)

Upvotes: 1

Seder
Seder

Reputation: 2763

There might be a lot of choices here to empty()

empty() Determine whether a variable is considered to be empty. A variable is considered empty if it does not exist or if its value equals FALSE. empty() does not generate a warning if the variable does not exist.

to overcome this issue you need to check the number of rows returned from the query because if it has no errors it will return true 

rowCount();

Check it out here

http://php.net/manual/en/pdostatement.rowcount.php

I hope this can help :)

Upvotes: 1

mlwacosmos
mlwacosmos

Reputation: 4541

empty should not work here. If your sql statement returns no result, the PDO::query method return an object anyway : a PDOStatement. But you can use rowCount to see if your statement is empty.

Upvotes: 1

Spudley
Spudley

Reputation: 168655

What exactly do you understand the empty() function to do? I guess you think it should tell you whether the query has any results or not. That is not what it does.

What empty() does is return true if the variable (in this case $result4) is null or contains some other "empty" value.

A recordset object is not an "empty" value, regardless of how many records it got.

What you probably want to use instead for this case is

if($result4->rowCount() > 0)

See the PHP manual for PDOStatement::rowCount.

empty() would only be useful here if you expected the query to fail completely -- eg an invalid query or broken DB connection. In that case, $result4 would be null. But you'd also have PDO errors that you'd use to deal with that rather than checking for the recordset object being empty.

Hope that helps.

Upvotes: 0

Related Questions