• PHP random number generation


    /*** random number generation * // / total number of numbers $num = 30// The number of rows is $rownum = 6$ arr = range(1, $num); shuffle($arr);$ i = 0; foreach ($arr as $val) { $i++; echo $val; if ($i >= $rowNum) { $i = 0; echo PHP_ EOL; } else { echo ‘ ‘; […]

  • How can laravel implement pseudo multiprocessing without using pcntl / pthreads / spool?


    introduction As we all know, multiprocess / multithread can execute multiple tasks in parallel / concurrent, which can improve the efficiency. PHP does not support multiprocessing / multithreading by default. You need to install the pcntl / pthreads extension to support it. If you don’t use the framework such as spool, the implementation is more […]

  • Practice SQL to summarize the total number of doctors under the organization


    Background:Practice SQL. Organization table and doctor table. Summarize the total number of doctors under each organization. Remove the doctor row with 0 under the organization and display it in reverse order SQL statement select DISTINCT b.InstitutionID,InstitutionName,COUNT(ClientID) ClientSum from b_Institution b left join b_Client c on c.InstitutionID = b.InstitutionID group by b.InstitutionID , InstitutionName having COUNT(ClientID) […]

  • Big data development – Data Warehouse ads layer index calculation


    Ads layer data is often the final result index data, which is used in large screen display or real-time stream processing. Practice how to write SQL in large screen display through the following two examples. 1. Member analysis case 1.1 data preparation The table structure is as follows. This table is a member table of […]

  • 01nginx simple configuration details


    1. Nginx command line parameters -C < / path / to / config > specifies a configuration file for nginx instead of the default. -T does not run, just tests the configuration file. Nginx will check the syntax of the configuration file for correctness and try to open the file referenced in the configuration file. […]

  • Amazing reversal! Hackers successfully steal $25 million from dforce and return it in full


    Technical editor: Zong enli from sifou newoffice SegmentFault has he reported the official account number: SegmentFault According to foreign media, nearly 25 million US dollars of assets were stolen from dforce, but then hackers returned almost all the funds to dforce, except for the loss of 1.2 million US dollars due to the conversion fee. […]

  • Mysql, sqlserver and Oracle specify the number of returned records


    Recently, new contacts with SQL server and Oracle database found that the total number of specified return records is actually different from mysql Mysql:select XXX where XXX limit N Sqlserver: select TOP N XXX Oracle:select XXXX where rownum < (N+1) Note: In Oracle, rownum = n, only n = 1 is true, others are false. […]

  • Application examples of two dimensional array in C language


    Today Xiaobian has prepared two examples. Let’s have a look! No.1   Question: The number of TV sets sold in six stores in a certain area in one month is shown in the table below,calculationandPrintingTV sales summary. The number of TV sets sold in six stores in one month 1 52 34 40 40 2 32 […]

  • How to increase the number of network connections in CentOS


    CentOS uses external access by default, and the total number of TCP links initiated is less than 28232. It can be calculated by the result of the following command $ cat /proc/sys/net/ipv4/ip_local_port_range What I get here is: 32768 60999 The subtraction of the two is equal to 28231, which means that the number of external […]

  • C practical exercise topic 21 – monkeys eat peaches


    Title:Monkey eat peach problem: the first day the monkey picked a number of peaches, immediately ate half, not addicted, and ate one more 
 the next morning, he ate half of the remaining peaches, and another one. I ate half and one of the leftovers of the previous day every morning. When I wanted to […]

  • One second minesweeping


    You can directly use CE to modify the total number of mines. The following is the memory address of the total number of mines directly modified through C ා /// PROCESS_ALL_ACCESS -> (STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0xFFF) public const int PROCESS_ALL_ACCESS = (STANDARD_RIGHTS_REQUIRED| (SYNCHRONIZE | 4095)); /// STANDARD_RIGHTS_REQUIRED -> (0x000F0000L) public const int STANDARD_RIGHTS_REQUIRED = […]

  • Grouping data


    1 Introduction Data is returned in groups, not in the type of where 2 create group by select vend_id, count(*) as num_prods from products group by vend_id; 2.1 analysis Press vend_ The ID field is grouped, and then the total number is counted and the data is returned 3 filtering grouping (having) select cust_id, count(*) […]