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mysqli - Undefined variable: con in D:\xampp\htdocs\user\p\andooze\include\dbconfig.php on line 15

Hey everyone,

I'm facing an issue with my PHP code and I could really use some help. I'm using MySQLi in my project, and I'm getting an "Undefined variable: con" error in my dbconfig.php file on line 15. I'm not sure what's causing this error and how to fix it.

To give you some context, I'm developing a user management system for my website. I have a separate file called dbconfig.php where I define my database connection details and create an instance of the MySQLi class. Here's the relevant code snippet where the error is occurring:

$servername = "localhost";
$username = "root";
$password = "";
$database = "mydatabase";

// Create connection
$con = new mysqli($servername, $username, $password, $database);

// Check connection
if ($con->connect_error) {
die("Connection failed: " . $con->connect_error);

I'm using this $con variable in my other PHP files to perform various database operations. However, when I include this dbconfig.php file in those files, the error pops up saying "Undefined variable: con" on line 15.

I've checked the code several times, and I can't seem to figure out why the $con variable is not recognized in my other files. Could it be an issue with the scope of the variable?

If any of you have encountered a similar problem or have any suggestions on how to resolve this, I would really appreciate your help. Thank you in advance!

All Replies


Hey everyone,

I understand the frustration that comes with encountering an "Undefined variable: con" error. I've faced a similar issue in the past, and it turned out that the error was caused by a simple typo in my dbconfig.php file.

Double-check your dbconfig.php file and ensure that you have correctly defined the $con variable. Look out for any typos, missing semicolons, or syntax errors that might be causing the variable to be undefined.

Another thing you can try is explicitly declaring the $con variable as global inside your other PHP files where you're using it. This will ensure that the variable is recognized and accessible within the scope of those files.

If none of these suggestions resolve the issue, it might be worth checking if there are any conflicting variable names or namespace issues in your code. Sometimes, variable names used elsewhere in your project can clash with the $con variable.

Lastly, consider checking your PHP configuration and ensure that MySQLi extension is enabled. If not, you can enable it in the php.ini file or contact your hosting provider for assistance.

I hope these tips help you in resolving the problem. Don't hesitate to ask if you need further assistance. Good luck!


Hey there!

I've encountered a similar issue before, and it took me a while to figure out what was causing it. In my case, the error was occurring because I had not properly included the dbconfig.php file in the file where I was trying to use the $con variable.

Make sure that you are including the dbconfig.php file in your PHP files where you intend to use the $con variable. You can do this by using the `include` or `require` statement.

Also, make sure that the path to the dbconfig.php file is correct. Double-check the file path to ensure that you are including the correct file.

If you have already done all of that, another possible reason for the error could be that your dbconfig.php file is not being executed before the file where you are using the $con variable. In that case, you may want to try using the `require_once` statement instead of `include` or `require` to ensure that the dbconfig.php file gets executed only once throughout your application.

I hope this helps! Let me know if you have any further questions.

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