[indo-oracle] single rows sub query return more than rows

[hery_777]

ini adalah code sql 

UPDATE TEMP_SELLOUT_MP_HY SET ID = (SELECT ID FROM REF_TOKO WHERE NAMA 
IN(SELECT NAMA_TOKO FROM TEMP_SELLOUT_MP_HY WHERE KOTA = 'YOGYAKARTA6' AND 
NAMA_MALL = 'RAMAIMALL')) WHERE KOTA = 'YOGYAKARTA6' AND NAMA_MALL = 'RAMAIMALL'



Error at line 1
ORA-01427: single-row subquery returns more than one row


Apa yang salah ya.???