What are the best practices for handling SQL queries with multiple selection criteria in PHP?

When handling SQL queries with multiple selection criteria in PHP, it is best to use parameterized queries to prevent SQL injection attacks and to ensure proper data handling. This can be achieved by using prepared statements with placeholders for the criteria values. Additionally, it is recommended to sanitize and validate user input before using it in the query to further enhance security. 

// Example of handling SQL queries with multiple selection criteria in PHP using parameterized queries

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

// Define criteria values
$param1 = 'value1';
$param2 = 'value2';

// Prepare SQL query with placeholders
$stmt = $pdo->prepare('SELECT * FROM mytable WHERE column1 = :param1 AND column2 = :param2');

// Bind criteria values to the placeholders
$stmt->bindParam(':param1', $param1);
$stmt->bindParam(':param2', $param2);

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

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

// Loop through results
foreach ($results as $row) {
    // Process each row
    echo $row['column1'] . ' - ' . $row['column2'] . '<br>';
}

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