Question 109116 in Json Question posted in
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Query key-value pairs from json in bigquery into a key and value columns

I have a JSON column in bigquery as such

SELECT PARSE_JSON('{"a": [1,2,3], "b":[4,5,6]}') AS key_values;

enter image description here

Is it possible to write a query such that I can get the following?

I can have any number of keys so I cannot specify the key name in my query.

enter image description here

Seems like this should be really simple but I cannot figure it out 🙁

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2

Answers


  1. 0

    You can use UNNEST operator along with CROSS JOIN s to have flattened result such as

    SELECT 'a' AS key, value
  FROM t,
       UNNEST(JSON_QUERY_ARRAY(json.a)) AS value
UNION ALL
SELECT 'b', value
  FROM t,
       UNNEST(JSON_QUERY_ARRAY(json.b)) AS value

    Demo

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  2. 0

    I cannot specify the key name in my query.

    you can consider below.

    CREATE TEMP FUNCTION json_keys(input STRING) RETURNS Array<String>
LANGUAGE js AS """
  return Object.keys(JSON.parse(input));
""";

CREATE TEMP FUNCTION json_values(input STRING) RETURNS Array<String>
LANGUAGE js AS """
  return Object.values(JSON.parse(input));
""";

WITH sample_data AS (
  SELECT '{"a": [1,2,3], "b":[4,5,6]}' AS key_values
)
SELECT k, v
  FROM sample_data,
UNNEST (json_keys(key_values)) k WITH offset JOIN
UNNEST (json_values(key_values)) v0 WITH offset USING(offset),
UNNEST (SPLIT(v0, ',')) v;

    Query results

    enter image description here

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