What are the advantages of using prepared statements over concatenating variables directly into SQL queries in PHP?

Using prepared statements in PHP helps prevent SQL injection attacks by separating SQL code from user input. This technique allows the database to distinguish between SQL code and data, making it safer to execute queries with user input. Prepared statements also improve performance by allowing the database to optimize query execution plans. 

// Using prepared statements to prevent SQL injection
$pdo = new PDO('mysql:host=localhost;dbname=mydatabase', 'username', 'password');

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

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

// Execute the query
$stmt->execute();

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

Keywords

Prepared statements SQL injection security PDO bindParam

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