Key value table to json in BigQuery

Question

Hey all,

I have a table that looks like this:

row	key	val
1	a	100
2	b	200
3	c	"apple
4	d	{}

I want to convert it into JSON:

{
    "a": 100,
    "b": 200,
    "c": "apple",
    "d": {}
}

Note: the number of lines can change so this is only an example

Thx in advanced !

Answer 1

With string manipulation,

WITH sample_table AS (
  SELECT 'a' key, '100' value UNION ALL
  SELECT 'b', '200' UNION ALL
  SELECT 'c', '"apple"' UNION ALL
  SELECT 'd', '{}'
)
SELECT '{' || STRING_AGG(FORMAT('"%s": %s', key, value)) || '}' json
  FROM sample_table;

You can get following result similar to your expected output.