What are the potential differences in PHP behavior between versions 5.4.7 and 5.2.1 that could affect PDO queries?

In PHP version 5.4.7, the default setting for the `PDO::ATTR_EMULATE_PREPARES` option was changed to `true`, which could affect the behavior of PDO queries compared to version 5.2.1 where the default setting was `false`. This change could lead to unexpected results or errors in queries that rely on prepared statements. To ensure consistent behavior between the two versions, you can explicitly set `PDO::ATTR_EMULATE_PREPARES` to `false` when establishing a PDO connection.

// Establish a PDO connection with the desired options
$pdo = new PDO($dsn, $username, $password, array(
    PDO::ATTR_EMULATE_PREPARES => false
));