sql - BigQuery 选择 * 两列除外

Question

我想从公共(public) BigQuery github_repos 数据集中选择除以下两条记录之外的所有内容:author.name AND Difference.old_mode。基于我问的类似问题，我想我想运行类似于的查询

#standardSQL
SELECT * REPLACE ((SELECT AS STRUCT author.* EXCEPT (name)) AS author), 
REPLACE ((SELECT AS STRUCT difference.* EXCEPT (old_mode)) AS difference)
FROM `bigquery-public-data.github_repos.commits`
LIMIT 1000;

如果我运行作者排除，效果很好:

#standardSQL
SELECT * REPLACE ((SELECT AS STRUCT author.* EXCEPT (name)) AS author)
FROM `bigquery-public-data.github_repos.commits`
LIMIT 1000;

但是，差异排除有错误:

#standardSQL
SELECT * REPLACE ((SELECT AS STRUCT difference.* EXCEPT (old_mode)) AS difference)
FROM `bigquery-public-data.github_repos.commits`
LIMIT 1000;

错误:

Dot-star is not supported for type ARRAY<STRUCT<old_mode INT64, new_mode INT64, old_path STRING, ...>> at [2:41]

谢谢。

更新 不是 SQL server 的重复项问题。

Answer 1

作为一个独立的示例，请考虑以下查询:

WITH T AS (
  SELECT 10 AS a, ARRAY<STRUCT<x INT64, y STRING, z BOOL>>[
      (1, 'foo', true)] AS arr UNION ALL
  SELECT 11, ARRAY<STRUCT<x INT64, y STRING, z BOOL>>[
      (2, 'bar', false), (3, 'baz', true)]
)
SELECT * FROM T;

它返回一列a类型 INT64和一列arr类型 ARRAY<STRUCT<x INT64, y STRING, z BOOL>> 。如果您想返回 arr 的修改其中数组内的结构省略 y ，您可以使用 SELECT * REPLACE 的组合和SELECT * EXCEPT :

WITH T AS (
  SELECT 10 AS a, ARRAY<STRUCT<x INT64, y STRING, z BOOL>>[
      (1, 'foo', true)] AS arr UNION ALL
  SELECT 11, ARRAY<STRUCT<x INT64, y STRING, z BOOL>>[
      (2, 'bar', false), (3, 'baz', true)]
)
SELECT * REPLACE(ARRAY(SELECT AS STRUCT * EXCEPT (y) FROM UNNEST(arr)) AS arr)
FROM T;

这个想法是用新数组替换原始数组，我们使用 ARRAY子查询 SELECT AS STRUCT和* EXCEPT使用字段不包含 y 的结构体元素重建数组.

回到问题中的查询，您可以将相同的想法应用于 difference和old_mode :

SELECT * REPLACE (
  ARRAY(SELECT AS STRUCT * EXCEPT (old_mode) FROM UNNEST(difference)) AS difference
)
FROM `bigquery-public-data.github_repos.commits`
LIMIT 1000;

查询结果包含difference其结构不包含 old_mode 的数组字段。