How to generate a unique order number in PHP _ PHP Tutorial

A summary of how PHP generates a unique order number. PHP generates a unique order number. The first code is as follows: returndate (Ymd ). str_pad (mt_rand (1,99999), 5, 0, STR_PAD_LEFT); the second code is as follows: returndate (Ymd ). summary of methods for generating unique order numbers in su PHP

First

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

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// 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, NNNNNNNN = random number, CC = check code @ Date_default_timezone_set ("PRC "); While (true ){ // Date of order $ Order_date = date ('Y-m-D '); // Subject of the order number (yyyymmddhhi1_nnnnnnn) $ Order_id_main = date ('ymdhis '). rand (, 9999999999 ); // Order number subject length $ 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.

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$ 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 first code of lifecycle is as follows: return date ('ymmd '). str_pad (mt_rand (1, 99999), 5, '0', STR_PAD_LEFT); the second code is as follows: return date ('ymmd '). su...