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Two tables Table A is A public curriculum with two fields, i.e. id and pro name. There are about five courses, and each of them should go to Table B is the association table of user and course reminders. It has four fields: ID, pro ID, user ID and tip time, which respectively represent ID, course ID, user ID and reminder class t ...

Dockerfile common instructions: 1. FROM: which image is used to build the imageFor example: FROM centos2. MAINTAINER: name or email address of image MAINTAINERFor example: maintainer sun Qi Ming3. RUN: the shell command to RUN when building the imageFor example:RUN [ "yum","install","httpd"]RUN yum -y install httpd4. CMD: shell command execute ...

Index and view details of Mysql database The concept of index The index of a database is similar to that of a BookIn a book, you can quickly find the required information by using the catalog without reading the whole bookThe table of contents in the book is a list of words with page numbers containing each wordDatabase indexIn the database, ...

VSFTP introduction VSFTP is a kind of FTP server software used on Unix like system published based on GPL. Its full name is Very Secure FTP. Software installation yum install vsftpd mariadb-server mariadb-devel pam-devel -y wget http://prdownloads.sourceforge.net/pam-mysql/pam_mysql-0.7RC1.tar.gz tar xf pam_mysql-0.7RC1.tar.gz cd pam_mysq ...

User service User service, providing login, registration, password modification and other functions. New service micro new shopping/user Finishing structure Add the model directory and repository directory, delete the default example folder in proto, and create the user folder. Development steps: 1. Define interface - > ...

Migration database is often encountered in work.If you use phpmyadmin to import, you can solve the problem if the database is too small. If it is too large, it will be troublesome. Either it will time out or the file is too large to import.So I chose to use Navicat For Mysql to copy the database In this process, I often encounter a problem: ERR ...

Setup of LAMP Environment Install DNS Server Install DNS Service yum install bind -y Configuration of DNS Create Forward Resolution For example, create a forward lookup zone named "lsy.com": Step 1: Create a lookup zone in the main configuration file/etc/named.conf. vim /etc/named.conf listen-on port 53{any ...

In the data source of spark, only Append, Overwrite, ErrorIfExists, Ignore are supported. But almost all of our online businesses need the upsert function, that is, the existing data must not be overwritten. In mysql, we use: ON DUPLICATE KEY UPDATE. Is there such an implementation? Official: sorry, no, dounine: I have it. You can ...

Indexes are often not used as expected in MySQL, and logging the use of an Order by statement today results in an index not being used as expected. 1. Problem phenomena 1.1 SQL statement: SELECT DISTINCT p.* FROM tb_name p WHERE 1=1 AND p.createDate >= '2019-10-23' AND p.createDate <= '2019-11-20 24:00:00' AND p.status = '1' AND p.a ...

Basic concepts of databases Data: Symbolic records describing things are called data. Include numbers, text, graphics, images, sounds, file records, etc. Store in a uniform format as a "record". Table: A table is formed by grouping different records together Is used to store specific data Database: A database is a collection of ...