How to create notification of posting like facebook?

[Linddha]

i want to show the notification of my posting.
but my script cann't working
i have 4 table - user, group, article, comment

user :
id_user username
1 | user1
2 | user2
3 | user3

group :
id_group name content
1 | Script
2 | Math

article :
id_news |id_group | title content
1 | 1 | PHP | how we can learn PHP?
2 | 2 | HTML | how we can learn html?
3 | 1 | PHPagain | how we can learn PHP again?

Comment
id_comment id_news comment
1 | 1 | in school we can learn PHP
2 | 1 | in my web we can learn PHP
3 | 2 | HTML is easy in w3schools
4 | 3 | in my web we can learn PHP again

Result :
Notification (3 comment)
1 Script - 2 comment (user1, user2)
2 Math - 1 comment (user3)

Sould i create new table? -table notification?
or only use query of my table?

[Lsmjudoka]

Facebook-style notifications revolve around the concept of "following" a post, which is done automatically when a user either A) Created the post, B) Likes the post, or C) Comments on the post.

I'm sure there's a more efficient way to do this but the simplest I can think of is to create another column for each article named users_following or similar and store the user IDs of the user who posted the article and the users who have commented on it inside(Can use JSON, serialization, CSV). Then when a new comment is made, send a notification to everyone on the list. Notifications should be inserted into a new notifcations table, which can contain a "read" column, this way you can check if the user already has a notification about the target article and avoid spamming them with notifications.

[Linddha]

so better if i create a notification table contain of read column and also the id of every table?

[Lsmjudoka]

The notification table should hold the id of the item(say, article) in addition to the text notification (e.g. "Matt Parker has commented on XXXXX Article"). For user-friendliness you should add a "read" column that stores whether the notification has been viewed or not - Then when making more notifications, you only send them(insert into the table) if there isn't already an unread notification for the same time. Like say if I already have a pending(unread) notification for article #63371, you don't send me more notifications for that article until my last one is marked as read.