第一种：

$danhao = date('Ymd') . str_pad(mt_rand(1, 99999), 5, '0', STR_PAD_LEFT);
结果:$danhao=2018112286649

第二种:

$danhao = date('Ymd').substr(implode(NULL, array_map('ord', str_split(substr(uniqid(), 7, 13), 1))), 0, 8);
 结果:$danhao=2018112297101975

第三种:

@date_default_timezone_set("PRC");
  $order_date = date('Y-m-d');
  $order_id_main = date('YmdHis') . rand(10000000,99999999);
  $order_id_len = strlen($order_id_main);
  $order_id_sum = 0;
  for($i=0; $i<$order_id_len; $i++){
  $order_id_sum += (int)(substr($order_id_main,$i,1));
  }
  $danhao = $order_id_main . str_pad((100 - $order_id_sum % 100) % 100,2,'0',STR_PAD_LEFT);
结果: $danhao = 201811220210291469007438

第四种:

$yCode = array('A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J');
$danhao = $yCode[intval(date('Y')) - 2011] . strtoupper(dechex(date('m'))) . date('d') . substr(time(), -5) . substr(microtime(), 2, 5) . sprintf('%02d', rand(0, 99));
结果: $danhao =HB22239188840352