1ALTER TABLE repos ADD COLUMN user_id INTEGER;
 2
 3UPDATE repos SET user_id = (
 4  SELECT id FROM users WHERE admin = true ORDER BY id LIMIT 1
 5);
 6
 7ALTER TABLE repos
 8ALTER COLUMN user_id SET NOT NULL;
 9
10ALTER TABLE repos
11ADD CONSTRAINT user_id_fk
12FOREIGN KEY(user_id) REFERENCES users(id)
13ON DELETE CASCADE
14ON UPDATE CASCADE;