Kopiering af MySQL-data og oprettelse af en ny post med en betingelse

du var tæt nok på. bare ændre new ind i combined .

INSERT INTO combined (ip, user_ID)
SELECT  old.ip, new.user_ID
FROM    old
        INNER JOIN new 
            on old.email = new.email;

OPDATERING 1

INSERT INTO combined (ip, user_ID, status)
SELECT  old.ip, new.user_ID, 'approved'
FROM    old
        INNER JOIN new 
            on old.email = new.email;