EMQ X rule engine series stores messages to MySQL database

Scenario introduction This scenario requires storing qualified messages under EMQ X specified topics into the MySQL database. In order to facilitate subsequent analysis and retrieval, message content needs to be split and stored. In this scenario, the device side reports the following information: Subject: cmd/state/:id, in which ID represents ...

Posted on Wed, 31 Jul 2019 04:50:41 -0700 by Drace

Java web login registration interface introductory tutorial

Preface: The blogger is a self-taught Java, but even the basic knowledge of "Java from Initial to Proficient" has not been read. Because of the need of internship, it is necessary to develop a simple login and registration interface with JavaEE (J2E). Through powerful search engine and num ...

Posted on Mon, 29 Jul 2019 02:25:58 -0700 by cordoprod

mysql log system inventory

MySql log files include error log, slow query log, transaction log, binary log, etc. Mysql logs can be configured by command 1 show global variables like '%log%'; The results of implementation are as follows "back_log" "80" "binlog_cache_size" "32768" "binlog_checksum" "CRC32" "binlog_direct_non_transactional_updates" ...

Posted on Sun, 28 Jul 2019 05:40:09 -0700 by scuzzo84

01 MySQL Complete Notes

MySQL I. Services System: services.mcs net start mysql open service net stop mysql closes the service mysql -uroot -p(pwd) -h127.0.0.1 3306 -P Link locality is abbreviated as: mysql-uroot-p passwd: hch II. Basic Operation 1. Operating folders or libraries: (The name of the repository cannot ...

Posted on Sat, 27 Jul 2019 23:29:40 -0700 by kimbeejo

Foundation Dynamic Planning

- Restore content to start Dynamic Programming Dynamic Programming Methodology _The essence of a computer is a state machine. All the data stored in memory constitute the current state. CPU can only calculate the next state by using the current state (don't tangle with external storage such as hard disk, even if they consider that they just exp ...

Posted on Sat, 27 Jul 2019 07:49:15 -0700 by algarve4me

python uses MYSQL database

The database will be used for testing. Today, I write an article about connecting MYSQL database through python.   What is MYSQL database MySQL is a relational database management system, developed by Swedish MySQL AB Company, and currently belongs to Oracle's products. MySQL is one of the most popular relational database management systems. ...

Posted on Sat, 27 Jul 2019 00:54:47 -0700 by pgsjoe

MYSQL II - Data Management (Foreign Key, Add or Delete)

Mysql: MySQL Data Management Foreign Key Management Foreign key concept If the public key is the primary key in a relationship, then the public key is called the foreign key in another relationship. Thus, foreign keys represent the correlation between the two relationships. A table with another fo ...

Posted on Sat, 27 Jul 2019 00:33:38 -0700 by schajee

Docker volume speed up npm install

The previous section decided to use Docker as the build environment in Jenkins, so that we could compile our project for all kinds of node versions we wanted. The problem of version switching is solved. However, Docker is designed for a clean execution environment, so every time a docker container is run, it is equivalent to a new system, so th ...

Posted on Fri, 26 Jul 2019 01:48:59 -0700 by meir4u

Vert.x Asynchronous Access to Database MySQL

Vert.x provides an API for asynchronous access to the database. Database operations are time-consuming and can easily block threads using the traditional synchronization model, resulting in overall performance degradation. Therefore, we need to use the asynchronous API provided by Vert.x for database operations. Vert.x provides a very low leve ...

Posted on Thu, 25 Jul 2019 12:44:04 -0700 by cfgcjm

LAMP Platform Deployment and Application

In the Internet, to provide a fully functional and extensible enterprise website server, not only HTTP server software, database system, but also dynamic web page program support are required.The LAMP platform integrates these services very well.As an enterprise operation and maintenance personnel, it is necessary to understand and master. Ove ...

Posted on Wed, 24 Jul 2019 10:10:00 -0700 by zipadee