PHP if query not behaving correctly

Question

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

What do you mean by an empty result? No rows returned?

Raz Harush
– Raz Harush

2013-05-21 15:33:06 +00:00
Commented May 21, 2013 at 15:33 — Raz Harush
– Raz Harush, Commented May 21, 2013 at 15:33

Bo A · Accepted Answer · 2015-06-27 15:15:44Z

3

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() ){

edited Jun 27, 2015 at 15:15

Bo A

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answered May 21, 2013 at 15:33

George Cummins

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1 Comment

themeparkfocus Over a year ago

This worked perfectly. It's my fault I'm really new to PHP but now I know how to use rowCount() Thanks

mlwacosmos · Accepted Answer · 2013-05-21 15:35:59Z

1

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.

answered May 21, 2013 at 15:35

mlwacosmos

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Comments

Seder · Accepted Answer · 2013-05-21 15:37:02Z

1

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 :)

answered May 21, 2013 at 15:37

Seder

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Comments

Fabio · Accepted Answer · 2013-05-21 15:42:16Z

1

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)

edited May 21, 2013 at 15:42

answered May 21, 2013 at 15:35

Fabio

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1 Comment

Bojangles Over a year ago

You need to clarify your explanation. The result of a query can be empty (no rows) but the PDOStatement object returned will never satisfy empty() != false

Spudley · Accepted Answer · 2013-05-21 15:34:45Z

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.

Marcos Tavares · Accepted Answer · 2013-05-21 17:21:15Z

0

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

answered May 21, 2013 at 17:21

Marcos Tavares

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