PHP: Prepare parameters for PDO Quries

gistfile1

<?php
/**
 * This function loops through the $_POST global and returns parameters that can be used in
 * a PDO statement directly. Note : For this function to work properly the 
 * PDO::ATTR_EMULATE_PREPARES should be set to "false"
 * like so "$conn->setAttribute(PDO::ATTR_EMULATE_PREPARES, false)".
 * @param  Array $exclude This is an array of keys in $_POST that you want the function to ignore
 * @return Array The function returns an array that can be used as parameters for the PDO statement
 */
function get_params($exclude = array()) {
	$keys = array();
	$values = array();
	$placeholder_keys = array();
	$params = array();

	foreach ($_POST as $key => $value) {
		if(!in_array($key, $exclude)) {
			$filtered_key		= filter_var($key);
			$keys[] 			= $filtered_key;
			$placeholder_keys[]	= ":" . $filtered_key;
			if(is_array($value)){
				$value = implode(",", $value);
			}
			$values[] = $value;
		}
	}

	$comma_sep_keys = implode(",", $keys);
	$comma_sep_placeholder_keys = implode(",", $placeholder_keys);

	$params['keys'] = $keys;
	$params['values'] = $values;
	$params['placeholder_keys'] = $placeholder_keys;
	$params['comma_sep_keys'] = $comma_sep_keys;
	$params['comma_sep_placeholder_keys'] = $comma_sep_placeholder_keys;

	return $params;
}