Database Design for Chat Application

What about temporary like 24hr story system

In the group_member table, I thought every record would need to have a primary key in order to be uniquely identifiable, but that table only has two foreign keys. Do those keys also serve the same purpose as a primary key then?

Why contact and group_member is not a many to many relationship?
One group can have multiple contacts, and one contact can be present in multiple groups

what if Message table have message_id, message_text, from_contact_id , to_contact_id, send_datetime and Group_member_Id fk . Group_member table have Group_member_Id , message_id fk and Contact_id fk.

I have three users and each user has a table. How will I do that here ?

But it will be a crazy query to get only 20 last msgs for specific conversations id, as it will need to filter a table from millions and millions other msgs. I dont know the right way right now, only know few with some pros and cons. Save all msgs as a json in field. But then it will be really hard to write new msgs each time. Other idea is to create for each conversations new table. But then it means we will have millions of tables in data base. But still i think this is the best aproach.

if we want single user to send a message and or send to to a group how will i do that here ?

nice erd for chat systems, will use yours and enhance it base to what i needed. thanks to your video

The whole video was special. You are a TOP G. Keep it up bro

Good stuff. However, how would you deal with figuring online users who need to be send messages to? Also, offline users, when they get online - how would this design help dispatch the missed messages to these users?

Really impressed... love this stuff...

شكراا

In this case how to identify the sender?

Good explanation

How do i differentiate single chat and group chat? tks

awesome stuff.. thanks for the clear explanation..
one question.. as the table grows, wont it be slower to query and fetch the chat messages if we store them in one table?

With messages being stored persistently and the above relational data model. Which database is most suitable for chat app?

Thanks for this video sir!!

Great

hey can you make bridge table with 2 EAV data model?