如何提取在 BigQuery 中存储为字符串的 JSON 数组

Question

我有一个与此类似的 JSON 数组

[{"key":"Email","slug":"customer-email","value":"abc@gmail.com"},{"key":"Phone Number","slug":"mobile-phone-number","value":"123456789"},{"key":"First Name","slug":"first-name","value":"abc"},{"key":"Last Name","slug":"last-name","value":"xyz"},{"key":"Date of birth","slug":"date-of-birth","value":"01/01/1990"}]

但棘手的部分是，这个数组存储为字符串。所以我认为第一步是将字符串转换为数组，然后将其取消嵌套，然后按照here中的方法进行操作@

我想知道这种方法是否可行，如果可行，我猜我面临的挑战是将字符串转换为数组。如果没有，或者您有更有效的方法，请提供帮助。谢谢

Answer 1

你试过json_extract_array

select json_extract_array(
  """[{"key":"Email","slug":"customer-email","value":"abc@gmail.com"},{"key":"Phone Number","slug":"mobile-phone-number","value":"123456789"},{"key":"First Name","slug":"first-  name","value":"abc"},{"key":"Last Name","slug":"last-name","value":"xyz"},{"key":"Date of birth","slug":"date-of-birth","value":"01/01/1990"}]""");

Answer 2

以下是 BigQuery 标准 SQL

#standardSQL
SELECT 
  id, 
  JSON_EXTRACT_ARRAY(json_string) AS json_array
FROM `project.dataset.table`   

如果适用于您的问题中的示例数据，如下所示

#standardSQL
WITH `project.dataset.table` AS (
  SELECT 1 id, '[{"key":"Email","slug":"customer-email","value":"abc@gmail.com"},{"key":"Phone Number","slug":"mobile-phone-number","value":"123456789"},{"key":"First Name","slug":"first-name","value":"abc"},{"key":"Last Name","slug":"last-name","value":"xyz"},{"key":"Date of birth","slug":"date-of-birth","value":"01/01/1990"}]' json_string
)
SELECT 
  id, 
  JSON_EXTRACT_ARRAY(json_string) AS json_array
FROM `project.dataset.table`   

输出是

Row id  json_array 
1   1   {"key":"Email","slug":"customer-email","value":"abc@gmail.com"}  
        {"key":"Phone Number","slug":"mobile-phone-number","value":"123456789"}  
        {"key":"First Name","slug":"first-name","value":"abc"}   
        {"key":"Last Name","slug":"last-name","value":"xyz"}     
        {"key":"Date of birth","slug":"date-of-birth","value":"01/01/1990"}  

从这一点开始 - 您可以使用您在问题中引用的 How do I parse value from JSON array into columns in BigQuery 中的解决方案