Oracle 从选择更新

我必须从一个选择中进行更新，我得到了这两个表中的这两行

T1

customer_number | trx number     | amount_due_remaining
____________________________________________________
309514          |MM1218881/2011  | 0
309514          |MM1218882/2011  | 0
309514          |MM1218903/2011  | 0
309514          |MM1218905/2011  | 0

T2

contract | numdoc         | import
___________________________________
309514 |MM1218881/2011  | 2000,77
309514 |MM1218882/2011  | 1000,45
309514 |MM1218903/2011  | 1000,23
309514 |MM1218905/2011  | 2500,12

我必须在T2中输入剩余导入的列amount\u due\u的T1值

我做这个查询

update dbestrconto T1
SET T1.IMPORTO = (
SELECT nvl(T2.AMOUNT_DUE_REMAINING,0)
FROM XXENE_V_CCML_TRANSACTIONS@XXENE T2
WHERE T2.customer_number=T1.contratto
AND T2.customer_number='3095614'
and T2.TRX_NUMBER=T1.NUMDOC
)

但是错了，请帮帮我

---

注意，Rodolfo

您正在更新所有行-您需要在更新中添加where子句

我建议改为使用合并

merge into dbestrconto  t1 
using xxene_v_ccml_transactions@xxene t2
on  (t2.customer_number=t1.contratto
and t2.trx_number=t1.numdoc)
when matched then update set 
    t1.importo = nvl(t2.amount_due_remaining,0)
where  t2.customer_number='3095614';

问候。哈基