ORACLE兩表關聯更新

創建如下表數據
select * from t1 ;

select * from t2;

現需求：參照T2表，修改T1表，修改條件爲兩表的fname列內容一致。
16.1 方式1，update
UPDATE T1
SET T1.FMONEY = (select T2.FMONEY from t2 where T2.FNAME = T1.FNAME)
WHERE EXISTS(SELECT 1 FROM T2 WHERE T2.FNAME = T1.FNAME);

實例：更新 PURCHASE_CONTRACT表中預算主體BUDGETSUBJECT ，參照 PURCHASE_CONTRACT1
UPDATE PURCHASE_CONTRACT T1
SET T1.BUDGETSUBJECT = (select T2.BUDGETSUBJECT from PURCHASE_CONTRACT1 T2 where T2.ID = T1.ID)
WHERE EXISTS(SELECT 1 FROM PURCHASE_CONTRACT1 T2 WHERE T2.ID = T1.ID) AND T1.BUDGETSUBJECT IS NULL