Code:
SELECT C.CONTACT_ID, P.PHONENR_ID, P.PHONETYPE_ENUMID
FROM CONTACT AS C
LEFT JOIN CONTACTPHONENR AS CP ON C.CONTACT_ID=CP.CONTACT_ID
LEFT JOIN PHONENR AS PN ON CP.PHONENR_ID=PN.PHONENR_ID
WHERE PN.PHONETYPE_ENUMID=4
AND C.CONTACT_ID=20057
i'm just guessing here, but if that doesn't work, maybe add a 'GROUP BY C.CONTACT_ID'
i'm not sure. if you find the answer, i'd be interested to know what works.
from contact co ,
contactphonenr mobilecoph left join phonenr mobilephone on
mobilephone.phonenr_id = mobilecoph.phonenr_id and mobilephone. and co.CONTACT_ID = mobilecoph.contact_id