在 BigQuery 上展平多个嵌套数组
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【中文标题】在 BigQuery 上展平多个嵌套数组【英文标题】：Flatten multiple nested arrays on BigQuery 【发布时间】：2021-04-14 02:17:02 【问题描述】：我有几列嵌套在 bigquery 表中的数组，如下所示：
marketing_table
+------+------------------+------------------+--------------------------------------------+------------------------------------+-------------------------------------+-------------+
|Row | effective_status | targeting.age_min| targeting.audience_network_positions.value | targeting.facebook_positions.value | targeting.instagram_positions.value | campaign_id |
+------+------------------+------------------+--------------------------------------------+------------------------------------+-------------------------------------+-------------+
| 1 | Active | 22 | classic | feed | stream | 1 |
| | | | instream video | video_feeds | story | |
| | | | | instant_article | explore | |
| | | | | instream_video | | |
| | | | | marketplace | | |
| | | | | story | | |
| 2 | WITH_ISSUES | 22 | classic | feed | stream | 1 |
| | | | instream video | video_feeds | story | |
| | | | | instant_article | explore | |
| | | | | instream_video | | |
| | | | | marketplace | | |
| | | | | story | | |
+------+------------------+------------------+--------------------------------------------+------------------------------------+-------------------------------------+-------------+
SQL 方案如下所示：
Field name, Type, Mode
-----------------------
effective_status, STRING, NULLABLE
targeting. age_min, INTEGER, NULLABLE
targeting. age_min, INTEGER, NULLABLE
targeting.audience_network_positions.value, RECORD, REPEATED
targeting. facebook_positions, RECORD, REPEATED
targeting.facebook_positions.value, STRING, NULLABLE
targeting. instagram_positions, RECORD, REPEATED
targeting.instagram_positions.value, STRING, NULLABLE
campaign_id, STRING, NULLABLE
我希望它展平所有嵌套数组，以便它们产生
marketing_table
+------+------------------+------------------+--------------------------------------------+------------------------------------+-------------------------------------+-------------+
|Row | effective_status | targeting.age_min| targeting.audience_network_positions.value | targeting.facebook_positions.value | targeting.instagram_positions.value | campaign_id |
+------+------------------+------------------+--------------------------------------------+------------------------------------+-------------------------------------+-------------+
| 1 | Active | 22 | classic | feed | stream | 1 |
| 2 | Active | 22 | instream video | video_feeds | story | 1 |
| 3 | Active | 22 | instream video | instant_article | explore | 1 |
| 4 | Active | 22 | instream video | instream_video | explore | 1 |
| 5 | Active | 22 | instream video | marketplace | explore | 1 |
| 6 | Active | 22 | instream video | story | explore | 1 |
| 7 | WITH_ISSUES | 22 | classic | feed | stream | 1 |
| 8 | WITH_ISSUES | 22 | instream video | video_feeds | story | 1 |
| 9 | WITH_ISSUES | 22 | instream video | instant_article | explore | 1 |
| 10| WITH_ISSUES | 22 | instream video | instream_video | explore | 1 |
| 11| WITH_ISSUES | 22 | instream video | marketplace | explore | 1 |
| 12| WITH_ISSUES | 22 | instream video | story | explore | 1 |
+------+------------------+------------------+--------------------------------------------+------------------------------------+-------------------------------------+-------------+
你们能告诉我如何使用 bigquery SQL 上的 unnest 参数正确地取消所有这些数组的嵌套吗？
【问题讨论】：
您能展示一下您的表格的结构吗？targeting.instagram_positions.value 列的预期结果看起来有点奇怪...
@SergeyGeron 我已经更新了我的问题，请看一下先生
【参考方案1】：
这样的东西应该可以工作。
select
t.effective_status,
t.targeting.age_min,
anp.value as anp_value,
fp.value as fp_value,
ip.value as ip_value,
t.campaign_id
from table t,
unnest(t.targeting.audience_network_positions) as anp,
unnest(t.targeting.facebook_positions) fp,
unnest(t.instagram_positions) as ip
【讨论】：
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