What are some common mistakes or misconceptions beginners might have when working with SQL queries in PHP?

One common mistake beginners make when working with SQL queries in PHP is not properly sanitizing user input, leaving their code vulnerable to SQL injection attacks. To prevent this, always use prepared statements with parameterized queries to securely pass user input to the database. 

// Incorrect way without sanitizing user input
$username = $_POST['username'];
$password = $_POST['password'];

$sql = "SELECT * FROM users WHERE username='$username' AND password='$password'";
$result = $conn->query($sql);

// Correct way with prepared statements
$username = $_POST['username'];
$password = $_POST['password'];

$stmt = $conn->prepare("SELECT * FROM users WHERE username=? AND password=?");
$stmt->bind_param("ss", $username, $password);
$stmt->execute();
$result = $stmt->get_result();

Keywords

SQL injection prepared statements PDO mysqli error handling

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