如何在 BigQuery 中取消嵌套多个数组？

Question

我有这个 json，它存储在 BigQuery 表中的 3 个字段令牌、问题、答案中

令牌：STRING，问题：STRING，答案：STRING

问题和答案是STRING，因为它们是动态字段。

token 字段只有一个值。

questions字段有dictionary对象，“fields”是list对象，有3个问题。

answers 字段是一个 list 对象，其中包含 3 个问题的答案，id 将用于将问题与答案进行匹配。下面是从 bigquery 下载的 JSON 文件

token          questions                                      answers
18e6d8e445     {"fields": [{"id": "L39FyvUohKDV", "properties": {}, "ref": "d8834652-3acf-4541-8354-1e3dcd716667", "title": "What did you think about the changes?", "type": "short_text"}, {"id": "krs82KgxHwGb", "properties": {}, "ref": "5b6e6796-635b-4595-9404-e81617d4540b", "title": "How useful is this feature turning out to be for you?", "type": "opinion_scale"}, {"id": "lBzHtCuzHFM4", "properties": {}, "ref": "b76be913-19b9-4b8a-b2ac-3fb645a65a5c", "title": "Your email address", "type": "email"}], "id": "SdzXVn", "title": "Google Shopping 5/4/18"}       [{"field": {"id": "L39FyvUohKDV", "type": "short_text"}, "text": "t", "type": "text"}, {"field": {"id": "krs82KgxHwGb", "type": "opinion_scale"}, "number": 10, "type": "number"}, {"email": "t@t.com", "field": {"id": "lBzHtCuzHFM4", "type": "email"}, "type": "email"}]
949b2c57e3     {"fields": [{"id": "krs82KgxHwGb", "properties": {}, "ref": "5b6e6796-635b-4595-9404-e81617d4540b", "title": "How useful is this feature turning out to be for you?", "type": "opinion_scale"}, {"id": "lBzHtCuzHFM4", "properties": {}, "ref": "b76be913-19b9-4b8a-b2ac-3fb645a65a5c", "title": "Your email address", "type": "email"}, {"id": "L39FyvUohKDV", "properties": {}, "ref": "d8834652-3acf-4541-8354-1e3dcd716667", "title": "What did you think about the changes?", "type": "short_text"}], "id": "SdzXVn", "title": "Google Shopping 5/4/18"}       [{"field": {"id": "krs82KgxHwGb", "type": "opinion_scale"}, "number": 10, "type": "number"}, {"email": "someone@mail.com", "field": {"id": "lBzHtCuzHFM4", "type": "email"}, "type": "email"}, {"field": {"id": "L39FyvUohKDV", "type": "short_text"}, "text": "they were awesome", "type": "text"}]             
146c49cdd6     {"fields": [{"id": "CxhfK22a3XWE", "properties": {}, "ref": "d8834652-3acf-4541-8354-1e3dcd716667", "title": "What did you think about the changes?", "type": "short_text"}, {"id": "oUZxPRaKjmFr", "properties": {}, "ref": "5b6e6796-635b-4595-9404-e81617d4540b", "title": "How useful is this feature turning out to be for you?", "type": "opinion_scale"}, {"id": "zUIP73oXpLD6", "properties": {}, "ref": "b76be913-19b9-4b8a-b2ac-3fb645a65a5c", "title": "Your email address", "type": "email"}], "id": "kaiAsx", "title": "a - b"}                        [{"field": {"id": "CxhfK22a3XWE", "type": "short_text"}, "text": "nice", "type": "text"}, {"field": {"id": "oUZxPRaKjmFr", "type": "opinion_scale"}, "number": 2, "type": "number"}, {"email": "foo@bar.com", "field": {"id": "zUIP73oXpLD6", "type": "email"}, "type": "email"}]        

@mikhail-berlyant 在下面提供了这个查询，这让我非常接近我的预期。我唯一遇到的问题是我无法得到答案。

SELECT distinct token, id, title AS question,
JSON_EXTRACT_SCALAR(CONCAT('{',a,'}'), '$.type') answer_type
--REPLACE(REGEXP_EXTRACT(b, r'"type":".+?"\s*,\s*".+?":(.+)'), '"', '') answer
FROM `v1-dev-main.typeform.responses`,
UNNEST(REGEXP_EXTRACT_ALL(JSON_EXTRACT(definition, '$.fields'), r'"title":"(.+?)"')) title WITH OFFSET pos1,
UNNEST(REGEXP_EXTRACT_ALL(JSON_EXTRACT(definition, '$.fields'), r'"id":"(.+?)"')) id WITH OFFSET pos2,
UNNEST(REGEXP_EXTRACT_ALL(answers, r'"field": {(.+?)}')) a WITH OFFSET pos3
--UNNEST(REGEXP_EXTRACT_ALL(answers, r'{(.+?),\s*"field":{.+?}')) b WITH OFFSET pos4
WHERE pos1 = pos2 
--AND pos3 = pos4 
AND id = JSON_EXTRACT_SCALAR(CONCAT('{',a,'}'), '$.id')   

这是上面查询的结果

token                       id             question       answer_type
146c43c81cd5780839d3cdd6    zUIP73oXpLD6    Your email address  email
146c493c1cd5780839d3cdd6    oUZxPRaKjmFr    How useful is this feature turning out to be for you?   opinion_scale
146c493c05d5780839d3cdd6    CxhfK22a3XWE    What did you think about the changes?   short_text
18e6d8e33df44a1aa451b445    lBzHtCuzHFM4    Your email address  email
18e6d8e33df44a1aa451b445    L39FyvUohKDV    What did you think about the changes?   short_text
18e6d0fa014bfa1aa451b445    krs82KgxHwGb    How useful is this feature turning out to be for you?   opinion_scale
a63b20df691c9a949b2c57e3    krs82KgxHwGb    How useful is this feature turning out to be for you?   opinion_scale
a63b20df691c9a949b2c57e3    lBzHtCuzHFM4    Your email address  email
a63b258ce0339a949b2c57e3    L39FyvUohKDV    What did you think about the changes?   short_text

现在，我只是想念答案。

Answer 1

以下示例针对 BigQuery 标准 SQL，并根据这些 json 字符串的格式对您的数据进行了一些假设 - 因此很可能需要对正则表达式进行一些调整。但它适用于以下虚拟数据

#standardSQL
WITH `project.dataset.table` AS (
  SELECT 12345 token, 
'''{"fields": [
    {"id":"1","title":"Question 1?"},
    {"id":"2","title":"Questions 2?"},
    {"id":"3","title":"Question 3?"}
  ]}''' questions,
'''[  
  {"type":"text", "text":"answer 1", "field":{"id":"1", "type":"short_text"}},
  {"type":"number", "number":42, "field":{"id":"2", "type":"opinion_scale"}},
  {"type":"email", "email":"an_account@example.com", "field":{"id":"3", "type":"email"}}
  ]''' answers 
)
SELECT token, id, title AS question,
  JSON_EXTRACT_SCALAR(CONCAT('{',a,'}'), '$.type') answer_type,
  REPLACE(REGEXP_EXTRACT(b, r'"type":".+?"\s*,\s*".+?":(.+)'), '"', '') answer
FROM `project.dataset.table`,
UNNEST(REGEXP_EXTRACT_ALL(JSON_EXTRACT(questions, '$.fields'), r'"title":"(.+?)"')) title WITH OFFSET pos1,
UNNEST(REGEXP_EXTRACT_ALL(JSON_EXTRACT(questions, '$.fields'), r'"id":"(.+?)"')) id WITH OFFSET pos2,
UNNEST(REGEXP_EXTRACT_ALL(answers, r'"field":{(.+?)}')) a WITH OFFSET pos3,
UNNEST(REGEXP_EXTRACT_ALL(answers, r'{(.+?),\s*"field":{.+?}')) b WITH OFFSET pos4
WHERE pos1 = pos2 
AND pos3 = pos4 
AND id = JSON_EXTRACT_SCALAR(CONCAT('{',a,'}'), '$.id')    

结果为

Row token   id  question        answer_type     answer   
1   12345   1   Question 1?     short_text      answer 1     
2   12345   2   Questions 2?    opinion_scale   42   
3   12345   3   Question 3?     email           an_account@example.com   

根据以下cmets更新

#standardSQL
WITH `project.dataset.table` AS (
  SELECT "12345" token, '{"fields": [{"id":"1","title":"Question 1?"},{"id":"2","title":"Questions 2?"},{"id":"3","title":"Question 3?"}]}' questions,'[  {"type":"text", "text":"answer 1", "field":{"id":"1", "type":"short_text"}},{"type":"number", "number":42, "field":{"id":"2", "type":"opinion_scale"}},{"type":"email", "email":"an_account@example.com", "field":{"id":"3", "type":"email"}}]' answers UNION ALL
  SELECT "18e6d8e33df440fa014bfa1aa451b445", '{"fields": [{"id": "L39FyvUohKDV", "properties": {}, "ref": "d8834652-3acf-4541-8354-1e3dcd716667", "title": "What did you think about the changes?", "type": "short_text"}, {"id": "krs82KgxHwGb", "properties": {}, "ref": "5b6e6796-635b-4595-9404-e81617d4540b", "title": "How useful is this feature turning out to be for you?", "type": "opinion_scale"}, {"id": "lBzHtCuzHFM4", "properties": {}, "ref": "b76be913-19b9-4b8a-b2ac-3fb645a65a5c", "title": "Your email address", "type": "email"}], "id": "SdzXVn", "title": "Google Shopping 5/4/18"}', '[{"field": {"id": "L39FyvUohKDV", "type": "short_text"}, "text": "t", "type": "text"}, {"field": {"id": "krs82KgxHwGb", "type": "opinion_scale"}, "number": 10, "type": "number"}, {"email": "t@t.com", "field": {"id": "lBzHtCuzHFM4", "type": "email"}, "type": "email"}]"' UNION ALL
  SELECT "a63b258ce03360df691c9a949b2c57e3", '{"fields": [{"id": "krs82KgxHwGb", "properties": {}, "ref": "5b6e6796-635b-4595-9404-e81617d4540b", "title": "How useful is this feature turning out to be for you?", "type": "opinion_scale"}, {"id": "lBzHtCuzHFM4", "properties": {}, "ref": "b76be913-19b9-4b8a-b2ac-3fb645a65a5c", "title": "Your email address", "type": "email"}, {"id": "L39FyvUohKDV", "properties": {}, "ref": "d8834652-3acf-4541-8354-1e3dcd716667", "title": "What did you think about the changes?", "type": "short_text"}], "id": "SdzXVn", "title": "Google Shopping 5/4/18"}', '[{"field": {"id": "krs82KgxHwGb", "type": "opinion_scale"}, "number": 10, "type": "number"}, {"email": "someone@mail.com", "field": {"id": "lBzHtCuzHFM4", "type": "email"}, "type": "email"}, {"field": {"id": "L39FyvUohKDV", "type": "short_text"}, "text": "they were awesome", "type": "text"}]"' UNION ALL
  SELECT "146c493c051a0a481cd5780839d3cdd6", '{"fields": [{"id": "CxhfK22a3XWE", "properties": {}, "ref": "d8834652-3acf-4541-8354-1e3dcd716667", "title": "What did you think about the changes?", "type": "short_text"}, {"id": "oUZxPRaKjmFr", "properties": {}, "ref": "5b6e6796-635b-4595-9404-e81617d4540b", "title": "How useful is this feature turning out to be for you?", "type": "opinion_scale"}, {"id": "zUIP73oXpLD6", "properties": {}, "ref": "b76be913-19b9-4b8a-b2ac-3fb645a65a5c", "title": "Your email address", "type": "email"}], "id": "kaiAsx", "title": "a - b"}', '[{"field": {"id": "CxhfK22a3XWE", "type": "short_text"}, "text": "nice", "type": "text"}, {"field": {"id": "oUZxPRaKjmFr", "type": "opinion_scale"}, "number": 2, "type": "number"}, {"email": "foo@bar.com", "field": {"id": "zUIP73oXpLD6", "type": "email"}, "type": "email"}]"'
)
SELECT token, id, title AS question,
  JSON_EXTRACT_SCALAR(CONCAT('{',a,'}'), '$.type') answer_type,
  COALESCE(JSON_EXTRACT_SCALAR(b, '$.text'),JSON_EXTRACT_SCALAR(b, '$.number'),JSON_EXTRACT_SCALAR(b, '$.email')) AS answer
FROM `project.dataset.table`,
UNNEST(REGEXP_EXTRACT_ALL(JSON_EXTRACT(questions, '$.fields'), r'"title":\s*"(.+?)"')) title WITH OFFSET pos1,
UNNEST(REGEXP_EXTRACT_ALL(JSON_EXTRACT(questions, '$.fields'), r'"id":\s*"(.+?)"')) id WITH OFFSET pos2,
UNNEST(REGEXP_EXTRACT_ALL(answers, r'"field":\s*{(.+?)}')) a WITH OFFSET pos3,
UNNEST(REGEXP_EXTRACT_ALL(REGEXP_REPLACE(answers, r'"field":\s*{.+?}', '"field": ""'), r'{.+?}')) b WITH OFFSET pos4
WHERE pos1 = pos2 
AND pos3 = pos4 
AND id = JSON_EXTRACT_SCALAR(CONCAT('{',a,'}'), '$.id') 

输出是

Row token                               id              question                                                answer_type     answer   
1   12345                               1               Question 1?                                             short_text      answer 1     
2   12345                               2               Questions 2?                                            opinion_scale   42   
3   12345                               3               Question 3?                                             email           an_account@example.com   
4   18e6d8e33df440fa014bfa1aa451b445    L39FyvUohKDV    What did you think about the changes?                   short_text      t    
5   18e6d8e33df440fa014bfa1aa451b445    krs82KgxHwGb    How useful is this feature turning out to be for you?   opinion_scale   10   
6   18e6d8e33df440fa014bfa1aa451b445    lBzHtCuzHFM4    Your email address                                      email           t@t.com  
7   a63b258ce03360df691c9a949b2c57e3    krs82KgxHwGb    How useful is this feature turning out to be for you?   opinion_scale   10   
8   a63b258ce03360df691c9a949b2c57e3    lBzHtCuzHFM4    Your email address                                      email           someone@mail.com     
9   a63b258ce03360df691c9a949b2c57e3    L39FyvUohKDV    What did you think about the changes?                   short_text      they were awesome    
10  146c493c051a0a481cd5780839d3cdd6    CxhfK22a3XWE    What did you think about the changes?                   short_text      nice     
11  146c493c051a0a481cd5780839d3cdd6    oUZxPRaKjmFr    How useful is this feature turning out to be for you?   opinion_scale   2    
12  146c493c051a0a481cd5780839d3cdd6    zUIP73oXpLD6    Your email address                                      email           foo@bar.com  

Answer 2

如果您确定数组的长度，可以先对它们进行 ARRAY_CONCAT 并使用串联版本执行 UNNEST。它对我有用。