Unnest 數組定義為 BigQuery 中一行內的字符串

Question

我有以下查詢

select 123 as user_id, "[\"A\",\"B\",\"C\"]" as category

生成此數據：

user_id       category
    123  ["A","B","C"]

我想從這些數據中得到的是：

user_id       category
    123              A
    123              B
    123              C

我該怎么做？

Answer 1

下面使用。

WITH sample_data AS (
  select 123 as user_id, "[\"A\",\"B\",\"C\"]" as category
)
SELECT user_id, category 
  FROM sample_data, UNNEST(JSON_VALUE_ARRAY(category)) category;