Is it possible to design a database table like this?

Question

MySQL

There is an email list for mailing, everything works like this: a user adds news / order, etc., you need to notify other users on the site about this, if these users are offline, letters are sent without delay, but if online, there is a delay (for example 3 minutes), if the user has not read the event on the site in 3 minutes, an email is sent to him, otherwise the email is removed from the list
You could do this:
news
id, name, author_id, text, email_id
orders
id, name, author_id, supplier_id, email_id
emails: id, author_id
, recipient_id, subject, text, time_to_send, created
Would it be correct to make the order_id, news_id, etc. fields in the emails table?
id, author_id, recipient_id, order_id, news_id, subject, text, time_to_send, created
What is the best way to proceed in this case?

Answer 1

If strict normalization is carried out, then there should be a table of letters (id, author_id, subject, text, created), a mailing table (letter_id, recipient_id, time_to_send). If the letters<->news and letters<->orders links are many-to-many, then two link tables (letter_id, news_id) and (letter_id, order_id), if not, then the news_id and order_id fields are also in the letters table. And then you need to look at whether denormalization is needed and to what extent.