attendance system for students using Qr image contains Student ID

Ok .. So i have 100 student in one class and its too hard to call everyone by his name to take attendance so i searched for easy way to make attendance automatically and i found online script [javascript] for scan qr and display it content so i will generate a qr image for every student contains his id and i will make a sql table contains some thing like

Table Name : Students  ----> 
- Unique Id
- Student Id
- Student Name

Table Name : subjects ----> 
- Unique Id
-Subject Code
-SUBJECT Name

Table Name : attend ----> 
- Unique Id
-Date
-Sign In : Default 0 [Absent]
-Sign Out : Default 0 [Absent]

so when the student scan his qr with the webcam i have .. his id will go to mysql and record attended so i can extract it as Excel file

this is qr scanner on github http://ift.tt/PR0IaG

will this be hard to this in php & mysql ?? please help me