How to use SELECT IFNULL in PDO? - php

Question

i was looking for a way to return an error if no results were found in a MySql query, at first i declared a variable value false, and if the fetch() function is true it will set the value of that boolean to true, then i check if it is true or false, but then i searched for that in internet cause i didn't like my solution that much, so I found the function IFNULL(query, 'error message');
I tried it but I had an error, can you tell me what's wrong in my code?
if(isset($_POST['tosearchfor']))
{
$query = $db->query('SELECT IFNULL( (SELECT * FROM searchfor WHERE title LIKE \'%'.$_POST['tosearchfor'].'%) , \'Sorry, no resluts found for : <strong>'.$_POST['tosearchfor'].'strong');
while($result = $query->fetch())
{
echo '<div class="result"><a class="title" href="#">'.$result['title'].'</a><span class="link"><span style="font-size:15px;position:relative;top:0.8px;padding-right:2px;">‣</span>https://www.qsoft.com/'.$result['link'].'</span><span class="details">'.$result['details'].'</span></div>';
}
}
else
{
echo 'Error : empty search';
}
Thank you.

Answer 1

Hey i used a different method not in youre query but with $query->rowCount().
Let's use the IF outside of the query :)
And the $db->prepare protect youre query, because never put a $_POST directly inside a query without protection.
if(isset($_POST['tosearchfor'])){
//We prepare the query
$query = $db->prepare("SELECT * FROM searchfor WHERE title LIKE '%:tosearch%'");
//We had parameters
$query->bindParam(':tosearch',$_POST['tosearchfor'], PDO::PARAM_STR);
//We execute the query
$query->execute();
//We retrieve the results in array of objects
$results = $query->fetchAll(PDO::FETCH_OBJ);
if (count($results) > 0) {
foreach ($results as $result){
echo '<div class="result">
<a class="title" href="#">'.$result->title.'</a>
<span class="link">
<span style="font-size:15px;position:relative;top:0.8px;padding-right:2px;">‣</span>
https://www.qsoft.com/'.$result->link.'
</span>
<span class="details">'.$result->details.'</span>
</div>';
}
} else {
echo 'Sorry, no resluts found for : <strong>'.$_POST['tosearchfor'].'</strong>';
}
}else{
echo 'Error : empty search';
}

Answer 2

The default result value of IFNULL(expr1,expr2) is the more “general”
of the two expressions, in the order STRING, REAL, or INTEGER.
You cannot evaluate a group of records with IFNULL. Something like below
Also instead of using direct substitution values, you could use below methods to avoid sql injection.
$stmt = $pdo->prepare('SELECT * FROM employees WHERE name = :name');
$stmt->execute(array(':name' => $name));
if(empty($stmt)){
return false;
}
foreach ($stmt as $row) {
// do something with $row
}
return result;
If this method return false then there is no search result.

Answer 3

Finally, this is my code, i also added max number of results 20.
$db = new PDO('mysql:host=localhost;dbname=search','root','');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
if(isset($_POST['tosearchfor']))
{
$query = $db->query('SELECT * FROM searchfor WHERE title LIKE \'%'.$_POST['tosearchfor'].'%\'');
for($i=0; $i<20; $i++)
{
if($result = $query->fetch())
{
echo '<div class="result">
<a class="title" href="#">'.$result['title'].'</a>
<span class="link">
<span style="font-size:15px;position:relative;top:0.8px;padding-right:2px;">‣</span>
https://www.qsoft.com/'.$result['link'].'
</span>
<span class="details">'.$result['details'].'</span>
</div>';
}
else
{
if($i==0)
{
echo 'Sorry, no resluts found for : <strong>'.$_POST['tosearchfor'].'</strong>';
}
}
}
}
else
{
echo 'Error : empty search';
}