问题描述
有没有办法删除/更新 bigquery 中的嵌套字段?
Is there a way to delete/update nested field in bigquery?
假设我有这些数据
wives.age wives.name name
21 angel adam
20 kale
21 victoria rossi
20 jessica
或在 json 中:
or in json:
{"name":"adam","wives":[{"name":"angel","age":21},{"name":"kale","age":20}]}
{"name":"rossi","wives":[{"name":"victoria","age":21},{"name":"jessica","age":20}]}
从上面的数据可以看出.亚当有两个妻子，名叫天使和羽衣甘蓝.如何:
As you can see from the data above.Adam has 2 wives, named angel and kale. How to:
- 删除羽衣甘蓝记录.
- 将 jessica 更新为 dessica
我试着用谷歌搜索这个，但找不到.我也尝试取消嵌套等，但没有运气.
I tried to google this, but can't find it. I also tried to unnest, etc but no luck.
之所以要这样做，是因为我们将数组插入到错误的记录中，并希望在某些条件下删除/更新数组数据.
The reason why we want to do this is because we insert the array to the wrong records and want to remove/update array data with some condition.
推荐答案
以下为 BigQuery Standard SQL
Below is for BigQuery Standard SQL
#standardSQL
WITH updates AS (
SELECT 'rossi' name, 'jessica' oldname, 'dessica' newname UNION ALL
SELECT 'rossi' name, 'victoria' oldname, 'polly' newname UNION ALL
SELECT 'adam' name, 'angel' oldname, 'jen' newname
), divorces AS (
SELECT 'adam' name, 'kale' wifename UNION ALL
SELECT 'adam' name, 'milly' wifename UNION ALL
SELECT 'rossi' name, 'linda' wifename
)
SELECT t.name,
ARRAY(
SELECT AS STRUCT
age,
CASE
WHEN NOT oldname IS NULL THEN newname
ELSE name
END name
FROM UNNEST(wives)
LEFT JOIN UNNEST(updates) ON t.name = u.name AND name = oldname
LEFT JOIN UNNEST(divorces) AS wifename ON t.name = d.name AND name = wifename
WHERE wifename IS NULL
) waves
FROM `project.dataset.table` t
LEFT JOIN (
SELECT name, ARRAY_AGG(STRUCT(oldname, newname)) updates
FROM updates GROUP BY name
) u ON t.name = u.name
LEFT JOIN (
SELECT name, ARRAY_AGG(wifename) divorces
FROM divorces GROUP BY name
) d ON t.name = d.name
您可以使用下面的虚拟数据测试/玩上面
You can test / play with above using dummy data as below
#standardSQL
WITH `project.dataset.table` AS (
SELECT 'adam' name, [STRUCT<age INT64, name STRING>(21, 'angel'), (20, 'kale'), (22, 'milly')] wives UNION ALL
SELECT 'rossi', [STRUCT<age INT64, name STRING>(21, 'victoria'), (20, 'jessica'), (23, 'linda')]
), updates AS (
SELECT 'rossi' name, 'jessica' oldname, 'dessica' newname UNION ALL
SELECT 'rossi' name, 'victoria' oldname, 'polly' newname UNION ALL
SELECT 'adam' name, 'angel' oldname, 'jen' newname
), divorces AS (
SELECT 'adam' name, 'kale' wifename UNION ALL
SELECT 'adam' name, 'milly' wifename UNION ALL
SELECT 'rossi' name, 'linda' wifename
)
SELECT t.name,
ARRAY(
SELECT AS STRUCT
age,
CASE
WHEN NOT oldname IS NULL THEN newname
ELSE name
END name
FROM UNNEST(wives)
LEFT JOIN UNNEST(updates) ON t.name = u.name AND name = oldname
LEFT JOIN UNNEST(divorces) AS wifename ON t.name = d.name AND name = wifename
WHERE wifename IS NULL
) waves
FROM `project.dataset.table` t
LEFT JOIN (
SELECT name, ARRAY_AGG(STRUCT(oldname, newname)) updates
FROM updates GROUP BY name
) u ON t.name = u.name
LEFT JOIN (
SELECT name, ARRAY_AGG(wifename) divorces
FROM divorces GROUP BY name
) d ON t.name = d.name
结果符合预期
name waves.age waves.name
adam 21 jen
rossi 21 polly
20 dessica
我希望您能够将上述应用到您的真实案例中 :o)
I hope you will be able to apply above to your real case :o)
这篇关于如何删除/更新bigquery中的嵌套数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！