你如何使用PHP在SQL查询中转义引号？

$string = "This is a 'test' string.";
$escaped_string = addslashes($string);
// 输出：This is a \'test\' string.

$sql = "INSERT INTO `table_name` (`column_name`) VALUES ('$escaped_string')";

$mysqli = new mysqli("localhost", "username", "password", "database");
$string = "This is a 'test' string.";
$escaped_string = mysqli_real_escape_string($mysqli, $string);
// 输出：This is a \'test\' string.

$sql = "INSERT INTO `table_name` (`column_name`) VALUES ('$escaped_string')";