What is user_org_id for?

[zc-devs]

Keeping in mind User-Org is Many-to-One relation, I've made some testing.

In Gitea I created an Organization gt with a Team gt-devs and repository gitea as well as an Org wp with a team wp-devs and repository woodpecker. Then I added user usr to the both teams. I logged in Woodpecker by usr user and added gitea and woodpecker repositories.
Seems all works and user can be member of multiple organizations.

Looking in database:

woodpecker_test=# select user_id, user_login, user_org_id from users order by user_id;
 user_id |    user_login    | user_org_id
---------+------------------+-------------
       2 | usr              |           2
(5 rows)

woodpecker_test=# select * from orgs;
 id | name | is_user | private
----+------+---------+---------
  2 | usr  | t       | f
  6 | gt   | f       | f
  7 | wp   | f       | f
(7 rows)

I wonder, what is the purpose of user_org_id then?

[qwerty287]

Every user also has an org model in the orgs table to simplify features like user secrets.
This column links the corresponding org to the user.
In your case, user usr (ID 2) has the org with ID 2, thus user_org_id is 2 too.

[zc-devs]

So, there is two types of Orgs: user and not user.
Relation between User and UserOrg (flag is_user=true) is One-to-One, right?
Relation between User and OtherOrg (flag is_user=false) is Many-to-Many, right? And this relation is not direct, but via some other entity like repository (maybe)?

[qwerty287]

Relation between User and UserOrg (flag is_user=true) is One-to-One, right?

Yes.

Relation between User and OtherOrg (flag is_user=false) is Many-to-Many, right? And this relation is not direct, but via some other entity like repository (maybe)?

Yes, AFAIK this is not stored to db, but done in https://github.com/woodpecker-ci/woodpecker/blob/main/server/cache/membership.go.