Used to strip CC/Bank information from a Formidable form error where it was getting stored.

wpdb_example.php

<?php
add_action('wp_head' , 'remove_cc_information');
function remove_cc_information() {
	global $wpdb;
	$db_table_name = $wpdb->prefix . 'frm_item_metas';
	$results = $wpdb->get_results("SELECT id, meta_value FROM {$db_table_name} WHERE field_id = '83'", ARRAY_A);

	// Loops through and unserializes data to strip out CC/CVC numbers then updates the DB
	foreach ( $results as $result) {

		$id = $result['id'];
		$meta_data = unserialize( $result['meta_value']);;
		$cc = $meta_data['cc'];
		if( $meta_data['cvc'] !== '') {
			$meta_data['cvc'] = '';
		}
		$cc = str_repeat('X', strlen($cc) - 4) . substr($cc, -4);
		$meta_data['cc'] =  $cc;
		$re_serialized_data =  serialize($meta_data);
		$wpdb->update($db_table_name, array( 'meta_value' => $re_serialized_data), array( 'id' => $id));
	}
	// Remove Routing number
	$wpdb->update($db_table_name, array( 'meta_value' => ''), array( 'field_id' => '84'));
	// Remove Account number
	$wpdb->update($db_table_name, array( 'meta_value' => ''), array( 'field_id' => '85'));

	echo 'Complete';
}