MQTT, Node-RED, Linux, Apache2, MySQL, PHP, Telegram, ESP32, ESP8266, Arduino

8 More Discussions You Might Find Interesting

1. Programming

Node-RED: Writing MQTT Messages to MySQL DB with UNIX timestamp

First, I want to thank Neo (LOL) for this post from 2018, Node.js and mysql - ER_ACCESS_DENIED_ERROR I could not get the Node-RED mysql module to work and searched Google until all my links were purple! I kept getting ER_ACCESS_DENIED_ERROR with the right credentials. Nothing on the web was...

2. Programming

Publish and Subscribe to AES-256 Encrypted MQTT Messages to Node-RED from PHP Scripts

Various Node-Red crypto modules do not work with PHP, so to send an encrypted message from a PHP script (in this case from a Ubuntu server) to Node-RED we need our own code. After a few hours of searching, testing various libs, more testing and debugging, I got this PHP to Node-RED code...

3. Infrastructure Monitoring

Using Node-RED and MQTT to Monitor Server and Application Stats

After setting up MQTT and testing some ESP8266 and ESP32 modules, where I noted that testing in Programming ESP32 (ESP-WROOM-32) as an MQTT Client Subscribed to Linux Server Load Average Messages, I was so impressed with MQTT that I installed MQTT on three different computers, instantly and...

4. Programming

ESP32 (ESP-WROOM-32) as an MQTT Client Subscribed to Linux Server Load Average Messages

Here we go.... Preface: ..... so in a galaxy far, far, far away from commercial, data sharing corporations..... For this project, I used the ESP-WROOM-32 as an MQTT (publish / subscribe) client which receives Linux server "load averages" as messages published as MQTT pub/sub messages....

5. Programming

NodeMCU ESP8266 Blynk SSL Application for Linux Server Load Averages

Here is a useful SSL (HTTPS) application for anyone with a remote Linux server they want to keep an eye on using Blynk and the NodeMCU ESP8266. This little app also works (have tested as well) on the WeMos D1 ESP8266 Arduino board. The NodeMCU setup could not be easier, just find a...

6. Programming

Arduino-cli - Uploading to Unknown Chinese Arduino Boards using the Arduino Command Line Interface

In my further exploration of Arduino, today I decided to install the arduino-cli on my mac today. https://github.com/arduino/arduino-cli I followed the instructions for macOS but when I got to this part: arduino-cli board list I got the dreaded "Unknown" Fully Qualified Board Name...

7. Web Development

Node.js and mysql - ER_ACCESS_DENIED_ERROR

This problem has been killing me all day, and I cannot solve it. Basically, I am using node.js with the mysql module and it will not connect to the database. Here is the JS code snippet in node.js: app.get("/test", function(req, res) { var mysql = require("mysql"); var con =...

8. Web Development

about php.ini and mysql linux

I can't use mysql .How should i config the file of php.ini . the message: Fatal error: Call to undefined function mysql_errno() in /var/www/html/inc/dv_clssql.php on line 129 how should i do? please help me

LEARN ABOUT PHP

mysql_errno

MYSQL_ERRNO(3)								 1							    MYSQL_ERRNO(3)

mysql_errno - Returns the numerical value of the error message from previous MySQL operation

SYNOPSIS

       Warning

	      This  extension  is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, the MySQLi or PDO_MySQL extension should
	      be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:

		     omysqli_errno(3)

		     o PDO::errorCode

       int mysql_errno ([resource  $link_identifier = NULL])

DESCRIPTION

	Returns the error number from the last MySQL function.

	Errors coming back from the MySQL database backend no longer issue warnings. Instead, use mysql_errno(3) to retrieve the error code.  Note
       that  this  function  only  returns  the  error	code  from  the  most  recently  executed MySQL function (not including mysql_error(3) and
       mysql_errno(3)), so if you want to use it, make sure you check the value before calling another MySQL function.

	      o $
		link_identifier -The MySQL connection. If the link identifier is not specified,  the  last  link  opened  by  mysql_connect(3)	is
		assumed. If no such link is found, it will try to create one as if mysql_connect(3) was called with no arguments. If no connection
		is found or established, an E_WARNING level error is generated.

	Returns the error number from the last MySQL function, or 0 (zero) if no error occurred.

       Example #1

	      mysql_errno(3) example

	      <?php
	      $link = mysql_connect("localhost", "mysql_user", "mysql_password");

	      if (!mysql_select_db("nonexistentdb", $link)) {
		  echo mysql_errno($link) . ": " . mysql_error($link). "
";
	      }

	      mysql_select_db("kossu", $link);
	      if (!mysql_query("SELECT * FROM nonexistenttable", $link)) {
		  echo mysql_errno($link) . ": " . mysql_error($link) . "
";
	      }
	      ?>

	      The above example will output something similar to:

	      1049: Unknown database 'nonexistentdb'
	      1146: Table 'kossu.nonexistenttable' doesn't exist

       mysql_error(3), MySQL error codes.

PHP Documentation Group 													    MYSQL_ERRNO(3)

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