What are some common mistakes beginners make when retrieving and displaying data from a database in PHP?

One common mistake beginners make when retrieving and displaying data from a database in PHP is not properly sanitizing user input, which can lead to SQL injection attacks. To prevent this, always use prepared statements with parameterized queries to securely retrieve data from the database. 

// Connect to the database
$pdo = new PDO('mysql:host=localhost;dbname=mydatabase', 'username', 'password');

// Prepare a statement with a parameterized query
$stmt = $pdo->prepare('SELECT * FROM users WHERE username = :username');

// Bind the parameter and execute the query
$stmt->bindParam(':username', $_GET['username']);
$stmt->execute();

// Fetch and display the results
while ($row = $stmt->fetch()) {
    echo $row['username'] . '<br>';
}

Keywords

SQL injection PDO prepared statements error handling data validation

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