Scan RFID and retrieved data from mySQL

Hello, I'm trying to make an electronic device. I'm giving out the example of the situation.

Situation:
Students have different classes in one semester. But, if they don't attend all the classes, they're not be able to take the exam. During the exam, they will bring their students ID before they enter the hall, they have to scan the card at a device, then the output of the device will shows the response on their attendances from mySQL database at every classes.

The progress will be;

All can Scan their card -> Retrieve Data from mySQL -> If they went to all the classes, Green LED will light up, If they don't, Red LED will light up.

I'm having a problem with the coding for Ethernet and how to retrieve mySQL data based on their UID.

If any of you can find any kind of example or soultion. Kindly help me :confused:

I'm having a problem with the coding for Ethernet and how to retrieve mySQL data based on their UID.

What problem?

Are you able to read the UID? Are you able to make a GET request, to execute some script on some server? What does the script do? What is the response from the server?

I'm having problem with connecting the database in my coding since I don't have any basic in using Ethernet or WiFi along with mySQL back then. I only know how to do the basics like LED blinking etc.

This IS the Programming section of the forum, where you are expected to post your code.

"I'm having problems" is useless information. "I can't do XXX" is more useful, but only if XXX is precisely defined.

Typically, you would have a PHP script on the server that does all the work, given a UID. Then, you could test the script without needing an Arduino. When the script is known to work, you make a GET request to execute that script, with the UID as part of the request, and you read, collect, and parse the server response.

Without seeing any code, or serial output, it is not at all clear what your problem is.