<?php $sql = 'SELECT color, shape, smell FROM vegetables'; pc_debug("[sql: {$sql}]"); // only printed if DEBUG is true $r = mysql_query($sql);
<?php define('DEBUG', 2); function pc_debug($message, $level = 0) { if (defined('DEBUG') && $level > DEBUG) { error_log($message); } } $sql = 'SELECT color, shape, smell FROM vegetables'; pc_debug("[sql: {$sql}]", 1); // not printed, since 1 < 2 pc_debug("[sql: {$sql}]", 3); // printed, since 3 > 2