SELECT 
    CASE WHEN b.cnt_man IS NOT NULL THEN b.cnt_man ELSE a.cnt_man1 END AS cnt_man,
    CASE WHEN b.tel_no IS NOT NULL THEN b.tel_no ELSE a.tel1 END AS tel1,
    CASE WHEN b.adr IS NOT NULL THEN b.adr ELSE a.adr2 END AS adr1 FROM
cust a LEFT JOIN cus_wh b ON a.cus_no = b.cus_no
AND A.SEND_WH ='0000' WHERE a.cus_no = 'A0032'