How to attach users to projects?

Question

Database design

There is a users table, there is a projects table in sql. It is necessary to make sure that a certain project would be under a certain user. How to do it?

Answer 1

users <---> projects
does one user have one project? one-to-one
one user has more than one project? one-to-many
many users per project? many-to-one
each user can have more than one project, and one project can have more than one user? many-to-many

Answer 2

Add the user_id field to the projects table and write the user id from the users table there.

Answer 3

See how references and foreign keys work

Answer 4

It is possible so .