What are best practices for handling user input in PHP scripts to prevent SQL injections?

When handling user input in PHP scripts to prevent SQL injections, it is important to use parameterized queries with prepared statements instead of directly inserting user input into SQL queries. This helps to sanitize the input and prevent malicious SQL code from being executed. 

// Example of using prepared statements to handle user input safely
$pdo = new PDO('mysql:host=localhost;dbname=database', 'username', 'password');

// User input
$userInput = $_POST['user_input'];

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

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

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

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

Keywords

PDO prepared statements input validation parameterized queries escaping.

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