在Oracle MERGE中使用该ID加入时更新ID

Question

表1：PERSON

ID, colx...

10
20
30
40
50
60

Table 2: TBL_MERGE

ID, colx..., Old_ID

 10, ...,    null
 20, ...,    null
300, ...,    30
 40, ...,    null
 50, ...,    null
600, ...,    60

我想根据此标准用表2（TBL_MERGE）更新表1（PERSON）。

伪代码：

if tbl_merge.old_id is not null and tbl_merge.old_id = person.id then
    person.id = tbl_merge.id

由于

Answer 1

UPDATE person p set ID = (SELECT t.ID FROM tbl_merge t where t.old_id = p.ID)
WHERE EXISTS (Select 1 FROM tbl_merge t where t.old_id = p.ID)