Question

I’ve got a question about a database design. I’m making a webpage where users can create events (i.e user ‘Jane’ creates an event called ‘My Birthday Party’).
Other users are able to join this event, so user ‘John’ could attend Janes event ‘My Birthday Party’.
In order for Jane to see who and how many guests (users) are coming to her birthday party is it necessary to create a relation table between users and events?

Let’s say 100 guests (users) are attending, that would require me to make 100 rows in a relation table which links each user to the event. Can this be done otherwise?

Thanks in advance, if anything is unclear please tell me 🙂

Answer 1

Yes, you will want to create a JOIN table for the users and the events. Similar to this:

create table users
(
    id int,
    name varchar(10) -- add other fields as needed
);

create table events
(
    id int,
    name varchar(10),
    e_owner_id int, -- userId of who created the event
    e_date datetime -- add other fields as needed
);

create table users_events  -- when user wants to attend a record will be added to this table
(
    u_id int,
    e_id int
);

Then to query, you would use something like this:

select *
from users u
left join users_events ue
    on u.id = ue.u_id
left join events e
    on ue.e_id = e.id;