Big Query 中的 JSON 问题

Question

I have scenario to parse the json data which is of one column in table. Issue is that below Response column as json generated by Datastore backup to BigQuery. It has '\\'attached to every data.

Reponse": "[
  {
    \"questionId\":5121566669012992,
    \"answereId\":0,
    \"answeredText\":\"Summer\"
  },{
    \"questionId\":5166851730440192,
    \"answereId\":0,
    \"answeredText\":\"Barcelona\"
  },{
    \"questionId\":6304057064947712,
    \"answereId\":0,
    \"answeredText\":\"Kitesurf\"
  }
]"

How do I parse the below to get value for questionId using BigQuery?

Answer 1

JSON_EXTRACT cannot return REPEATED field, it can only do one match - hence no support for *

you can get the first position using hardcoded indexes as

SELECT JSON_EXTRACT_SCALAR('[
  {
    \"questionId\":5121566669012992,
    \"answereId\":0,
    \"answeredText\":\"Summer\"
  },{
    \"questionId\":5166851730440192,
    \"answereId\":0,
    \"answeredText\":\"Barcelona\"
  },{
    \"questionId\":6304057064947712,
    \"answereId\":0,
    \"answeredText\":\"Kitesurf\"
  } 
]', '$[0].questionId') AS str;

This returns:

+-----+------------------+---+
| Row |       str        |   |
+-----+------------------+---+
|   1 | 5121566669012992 |   |
+-----+------------------+---+