PHP method for generating unique order numbers

There was an e-commerce project a while ago and an order number needs to be generated. At that time, it was easy to consider adding a random number to the system time or using the uniqid () method. After careful consideration of the above method, the possibility of duplicate orders is zero when the customer buys a small amount, but the first type is generated during the purchase of beebot

The code is as follows:

Return date ('ymmd'). str_pad (mt_rand (1, 99999), 5, '0', STR_PAD_LEFT );

Second

The code is as follows:

Return date ('ymmd '). substr (implode (NULL, array_map ('ord ', str_split (substr (uniqid (), 7, 13), 1), 0, 8 );

Third

// Generate 24-bit unique order number, format: YYYY-MMDD-HHII-SS-NNNN, NNNN-CC, where: YYYY = year, MM = month, DD = date, HH = 24 format hour, II = minute, SS = second, nnnnnnnnnn = random number, CC = check code @ date_default_timezone_set ("PRC"); while (true) {// order date $ order_date = date ('Y-m-D'); // order number subject (yyyymmddhhi1_nnnnnnn) $ order_id_main = date ('ymdhis '). rand (, 99999999); // length of the subject of the order number $ 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);} // unique order number (yyyymmddhhi1_nnnnnnncc) $ order_id = $ order_id_main. str_pad (100-$ order_id_sum % 100) %, 2, '0', STR_PAD_LEFT );

Fourth:

After searching for a redtamo on the Internet, I found this student had a good idea. please take a look at the details. I will give a brief overview, this method uses English letters, year, month, and day, Unix timestamps, microseconds, and random numbers. the possibility of repetition is greatly reduced, which is quite good. The use of letters is very representative, a letter corresponds to a year, a total of 16 characters, not many also a lot, haha.

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

Effect:

The code is as follows:

A422694333616096

Alas, but unfortunately, this method is not used in the final project. it is said that it is not necessary to make such a complicated project ,--!

The above four methods are all shared in this article. I hope you will like them.