you need just little concept
just follow these steps
1.You need to add a fiels of ratind_date and IP field
2. then u should get the IP of the client by just using this
$_SERVER['REMOTE_ADDR']
now u need to compare three things
1. rating date
2. IP
3. artical
simple if on current date the ip vote the artical then do not insert vote else vote it
artical_user_ip=$strIp && artical_id=$strArtical
&& dated=Currentdate then
no vote
else vote
i hope u under stand
by
🙁