The scheme of self increasing in Laravel

In the work, a series of data are often added automatically, and a scenario is envisaged.A total of 10 coupons will be issued (the following operations are in time series)1) user 1 requests to receive 1 coupon;2) process 1 queries the remaining 10 coupons in the database, and the code updates the number of coupons. At this time, the number of ...

Posted on Mon, 11 Nov 2019 14:58:14 -0500 by sholtzrevtek

MySql Paging Query

Paging queries can be found everywhere on the web, so what's the principle?The following is a brief introduction to the implementation of limit based on MySql database. First, make sure why you want to use paging queries, because the data is so large that queries cannot be displayed on all pages. If they are displayed on all pages, it will also ...

Posted on Mon, 11 Nov 2019 12:39:38 -0500 by deathrider

iaas (openstack) super detailed setup and installation of Glance image service

Note: update with the previous blog Because the whole open source openstack installation process is too tedious, the command is too long, too tedious, so the entire installation command is written as a shell script. Too many scripts have been pushed github Source hosting center. This is the content of this script github Warehous ...

Posted on Mon, 11 Nov 2019 11:38:11 -0500 by JC99

Crawling the position information of the network based on selenium

1.selenium Selenium Is a tool for Web application testing. Selenium tests run directly in the browser, just as real users do. This feature provides a choice and direction for the development of crawlers. Because it depends on the browser itself, the premise of using the selenium Library of Python is that you need to download the corresponding ...

Posted on Mon, 11 Nov 2019 10:23:15 -0500 by mrjiggyhill

New feature of Oracle 12c -- LOGTIME parameter of data pump command

concept   The new LOGTIME command-line parameter available in Oracle Data Pump Export and Import allows you to request that messages displayed during export and import operations be timestamped. The valid values are: NONE - no timestamps on status or log file messages (same as the default) STATUS - timestamps on status mes ...

Posted on Mon, 11 Nov 2019 09:47:18 -0500 by LuiePL

Getting started with Python 3 concurrent programming

I. Python thread module 1. Thread introduction A standard thread consists of thread ID, current instruction pointer (PC), register set and stack. Thread is an entity in the process, which is the basic unit independently scheduled and dispatched by the system. The thread itself does not have system resources, and shares all the resources of the ...

Posted on Mon, 11 Nov 2019 08:18:09 -0500 by danwatt

Do programmers really understand the reflex mechanism?

Catalog Preface 1. Overview of reflection 2. Class CLASS Class CLASS Class KINDS BEFORE FORMAL USE OF REFLECTION 3. Use of reflection Preface Many blog posts explaining reflection do not elaborate on the Class class, ~including me before of course,~. Such posts only make reflection superfici ...

Posted on Sun, 10 Nov 2019 19:42:35 -0500 by copernic67

java instance understands the concept of blockchain

The core of blockchain is decentralized storage. Traditional database solutions, including relational database and non relational database, belong to centralized storage. Decentralized storage means that there is no data center, and each data node contains the information of the previous data node. An example is given to understan ...

Posted on Sun, 10 Nov 2019 16:38:52 -0500 by karan23424

Android development operation database

Android's database is SQLite, and the sql statements used are all interoperable. Let's not talk about it here. Look at the code: static ArrayAdapter adapter; ImageView img; Button add; Button delete; Button updata; Button select; ListView liv; SQLiteDatabase db; ArrayList<User> us ...

Posted on Sun, 10 Nov 2019 14:58:36 -0500 by pesale86

GreenPlum's events II: GreenPlum starts reporting errors

Labels (space delimited): GreenPlum In the process of configuring GreenPlum, you need to pay attention to the following points: Find the installation package Installation dependency, Gun version needs attention Detailed installation procedure reference Greenplum installation introduction I am a computer virtual machine insta ...

Posted on Sun, 10 Nov 2019 14:42:13 -0500 by antisback