我在SQL中执行了以下迁移请求：

UPDATE table1
SET table1.value = table2.value
FROM table1
INNER JOIN table2
ON table2.othervalue2 = table1.key
WHERE table2.othervalue3 is NULL

很好用。但不能用Oracle。我知道用Oracle在更新中做join不是不可能的，所以我用这个：

UPDATE table1 SET table1.value = (SELECT table2.value
                                  FROM table2
                                  WHERE table2.othervalue2 = table1.key
                                  AND table2.othervalue3 is NULL)
WHERE EXISTS (SELECT table2.value
                                  FROM table2
                                  WHERE table2.othervalue2 = table1.key
                                  AND table2.othervalue3 is NULL)

但我有一个ORA-01427：子查询返回多行。
谢谢