There's a defined function that you can call to check if it's already defined before defining it in your loop.

foreach($db as $key  =>  $value)
{
    if(!defined(strtoupper($key))){ define(strtoupper($key), $value); }
}

You can also use either an include_once or require_once with your db.php file so you don't accidentally include it twice and run into this problem in the first place...

Constant DB_HOST already defined, There's a defined function that you can call to check if it's already defined before defining it in your loop. You can also use either an include_once or require_once with your db. php file so you don't accidentally include it twice and run into this problem in the first place Founded as a Federally Chartered University in July 2000, the National University of Computer and Emerging Sciences is a premiere University of Pakistan.

Please check key is already defined or not using defined

chnage

define(strtoupper($key), $value);

to

 defined(strtoupper($key)) ||  define(strtoupper($key), $value);

Notice: Constant DB_USER already defined, Notice: Constant DB_HOST already defined in C:\mysqli.php on line 10 So, per the error message, the constants are defined in mysqli.php. PHP Notice: Constant FOO already defined in Checking to see if a constant has been defined with PHP. Checking to see if a function has already been defined in PHP is done using the defined() function which works in a similar way to the define() function. A single parameter is passed in which again needs to be a single or double quoted string.

Try This...

?php
     define('DB_HOST','localhost');
     define('DB_USER','root');
     define('DB_PASS','');
     define('DB_NAME','cms');  

    $conn = mysqli_connect(DB_HOST,DB_USER,DB_PASS,DB_NAME);

         if(!$conn){
          echo"Could not connect: ".mysql_error();
     } 
?>

OR

foreach($db as $key  =>  $value)
{
    if(!defined(strtoupper($key))){ define(strtoupper($key), $value); }
}

PHP Notice: Constant DB_USER already defined in phar:///usr/local , PHP Notice: Constant DB_USER already defined in phar:///usr/local/bin/wp/php/ wp-cli.php(23) : eval()'d code on line 13 #2180. Closed. IPE Cycle Review Panel Visited Members Review Panel HEC / Self-constituted Panel; 2017-18 (Peshawar) 1st: 2-3-4-Apr-2019: 1. Prof. Dr. Muhammad Abid , Dean, Faculty of Numerical and Physical Sciences, University of Peshawar, Peshawar.

[SOLVED] Constant HTTPS_SERVER already defined in error log , PHP Notice: Constant HTTPS_SERVER already defined in /home/coo/ public_html/sales/config.php on line 7 LInes in config are. 2 // HTTP Event Title Date Venue; Seminar: QEC-PWR organized and facilitated with HR department of Islamabad Campus to manage 1-Day Training Workshop on "Customer service Excellence" for non-teaching staff, batch IV, of Peshawar campus.

Really Confused!, Notice: Constant DB_HOST already defined in Secondly, it's not using your constants because they're already defined (obviously incorrectly)� Notice: Constant DS already defined in C:\wamp\www\game-template\modules\mod_tabs_gk5\admin\elements\configmanager.php on line 5 I have installed the Joomla 3.3 version of Game Quickstart package in my localhost. Here are the screen dumps:

Use of undefined constant DB_USER, define( 'DB_USER', 'something' );. The same for DB_NAME, DB_HOST, etc. vespino. (@vespino). 1� That file and line number is where the constant is being defined a 2nd time, not the original. On that line you’ll see something like define( 'FS_METHOD', **something** ); . The problem is that this line, or something very similar, must already be in that file, and you can’t have it twice.

Comments

• Run it though array_unique before looping for it. Also define is really slow and the fact that you are using enough of them to need a loop is concerning. Your problem resides elsewhere in your code. Probably a include instead of include_once.
• @AlexBarker is right if you are including this connection files to each pages than you should include it once.
• please mark as help ful this answer and give upvote this answer if its work for you THANK YOU!!!!@Sarthak Raval Happy coding :)