How can PHP developers ensure that user input is not malicious, such as preventing SQL injection attacks?

To prevent SQL injection attacks, PHP developers can use prepared statements with parameterized queries. This technique allows developers to separate SQL code from user input, effectively preventing malicious input from altering the SQL query structure. 

// Establish a database connection
$pdo = new PDO('mysql:host=localhost;dbname=mydatabase', 'username', 'password');

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

// Bind the user input to the parameter placeholder
$stmt->bindParam(':username', $_POST['username']);

// Execute the prepared statement
$stmt->execute();

// Fetch the results
$results = $stmt->fetchAll();

Keywords

PHP user input validation SQL injection prepared statements parameterized queries

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