oracle如何合并两行

Question

我有一个包含多条记录的表。一条记录有一些数据，另一条有一些数据并更新了

ID	Name	gender	birthday	address	salary
1	Jhon	null	null	newyork	null
2	Jhon Deo	Male	1980	null	5000

我在另一个表中使用了 id 1 作为外键，所以我需要它。但是 id 2 有更多更新的数据。

我想将两条记录合并为 id 1 并删除 2

ID	Name	gender	birthday	address	salary
1	Jhon Deo	Male	1980	newyork	5000

Answer 1

您应该能够使用这些语句清除额外记录 (ID 2)。请务必将以下语句中的 your_table 替换为您的实际表名。

UPDATE your_table t1
   SET (name,
        gender,
        birthday,
        address,
        salary) =
           (SELECT nvl(t2.name, t1.name),
                   nvl(t2.gender, t1.gender),
                   nvl(t2.birthday, t1.birthday),
                   nvl(t2.address, t1.address),
                   nvl(t2.salary, t1.salary)
              FROM your_table t2
             WHERE t2.id = 2)
 WHERE t1.id = 1;

DELETE FROM your_table
      WHERE id = 2;

Answer 2

如果要优先考虑最新的id：

select distinct
       last_value(name ignore nulls) over (order by id desc) as name,
       last_value(gender ignore nulls) over (order by id desc) as gender,
       last_value(birthday ignore nulls) over (order by id desc) as birthday,
       last_value(address ignore nulls) over (order by id desc) as address,
       last_value(salary ignore nulls) over (order by id desc) as salary
from t;