How Can You Check the Existence of a Row in a Database Using PDO?

How to Check Row Existence in a Database Using PDO

When attempting to perform an action conditional on the absence of a specific row in a database, you may encounter difficulties with using traditional methods like count($row) == 0 or if($stmt->rowCount() < 0).

A more effective approach is to directly examine the return value of the query. The following code snippet illustrates this technique:

<code class="php">$stmt = $conn->prepare('SELECT * FROM table WHERE ID=?');
$stmt->bindParam(1, $_GET['id'], PDO::PARAM_INT);
$stmt->execute();
$row = $stmt->fetch(PDO::FETCH_ASSOC);

if( ! $row)
{
    echo 'nothing found';
}</p>
<p>This method will return true if the row exists in the database, and false if it does not.</p>
<p>For checking the existence of multiple rows, you can use the fetchAll() method:</p>
<pre class="brush:php;toolbar:false"><code class="php">$rows = $stmt->fetchAll(PDO::FETCH_ASSOC); // Same here
if( ! $rows)
{
    echo 'nothing found';
}</code>

In situations where you wish to avoid fetching data, you can configure MySQL to return a boolean value by using the following query:

<code class="php">$sql = 'SELECT 1 from table WHERE id = ? LIMIT 1';
$stmt = $conn->prepare($sql);
$stmt->execute([$_GET['id']]);

if($stmt->fetchColumn()) echo 'found';</code>

This method will return a non-zero value if the row exists in the database and false otherwise.

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