What are the implications of not setting a FETCH mode when establishing a database connection in PHP and how can it affect dropdown menu values?

If a FETCH mode is not set when establishing a database connection in PHP, it can default to a mode that may not return the desired results when fetching data from the database. This can affect dropdown menu values if the data retrieved is not in the correct format or structure for populating the dropdown options. To solve this issue, you should explicitly set the FETCH mode to ensure that the data is retrieved in the format needed for your dropdown menu values.

// Establish a database connection with FETCH mode set
$pdo = new PDO("mysql:host=localhost;dbname=mydatabase", "username", "password", array(PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC));