Postgresql 如何使用PSQL中相同id的上次填充来填充空值？

我在PostgreSQL中有一个数据帧，如下所示，我想要每个id的最新记录，如果每个id的任何最新记录在任何列中都包含空值，我想用同一列中的下一个最新值替换它

资料

预期产量

最终输出

id    ingdt         code  gender  address   
1     27-10-2018    1234  M       street1   
2     24-10-2018    2857  F       Bstreet
3     24-08-2018    3489  M       Cstreet

尝试

使用可以帮助您：

SELECT DISTINCT
    id, 
    max(ingdt) OVER (PARTITION BY id),
    first_value(code) OVER (PARTITION BY id ORDER BY code IS NULL, ingdt DESC) AS code,
    first_value(gender) OVER (PARTITION BY id ORDER BY gender IS NULL, ingdt DESC) AS gender,
    first_value(address) OVER (PARTITION BY id ORDER BY address IS NULL, ingdt DESC) AS address
FROM mytable
ORDER BY id

解释（…）上的第一个值（…）：

窗口函数可以将行分组到单独的帧中。这是通过关键字

partitionby

完成的。在这种情况下，我为每个

id

生成帧

现在我正在检查列的值是否为

NULL

。这给了我

true

或

false

。我像任何

boolean

列一样对这个结果进行排序，并首先使用

false

（意思是

不为NULL

）。如果有许多

notnull

行，则取最新的一行（

ingdt DESC

）。此订购也针对每个单独的机架进行

first\u value（）

计算有序帧的第一个值

insert into final_output select * from (
(select code, id from data where code != null order by ingdt limit 1) x join
(select gender, id from data where gender != null order by ingdt limit 1) y join 
(select address, id from data where address != null order by ingdt limit 1)z on y.id=x.id)

SELECT DISTINCT
    id, 
    max(ingdt) OVER (PARTITION BY id),
    first_value(code) OVER (PARTITION BY id ORDER BY code IS NULL, ingdt DESC) AS code,
    first_value(gender) OVER (PARTITION BY id ORDER BY gender IS NULL, ingdt DESC) AS gender,
    first_value(address) OVER (PARTITION BY id ORDER BY address IS NULL, ingdt DESC) AS address
FROM mytable
ORDER BY id