BigQuery：如何计算 REPEATED 字段中的特定值？

Question

我在 BigQuery 表中有一个 STRING REPEATED 字段。

这是此类字段的行列表：

• “A”
• "A","C","E"
• "B,"E"
• "A","B","D"
• "D","E"

如何统计所有单个值的出现总数？

我尝试使用“GROUP BY”，但似乎无法对 REPEATED 字段进行 GROUP BY

Answer 1

你想 UNNEST 然后计数：

SELECT x, COUNT(*) AS c
FROM T, UNNEST(array_column) AS x
GROUP BY x