how do I update semi structured data in snowflake? - json

Question

We store a fair amount of value/pairs in a json object within a snowflake column.
The quantity of value/pairs is not pre-defined (hence semi structured data)
What are my options to update one of the value pairs?
Am I supposed to extract the entire JSON, convert it to string, modify the string and update the object column entirely?
Or is there a nice little function where I could update just the pair(s) I want?
create or replace table TB as
select $1 TB_ID, parse_json($2) my_json
from values
(1, '{ "FruitShape":"Round", "FruitSize":55 } '),
(2, '{ "FruitShape":"Square" } '),
(3, '{ "FruitShape":"Oblong", "FruitSize":22, "FruitColor":"Chartreuse" })
;
This created 3 rows with up to 3 value/pairs per row.
Let's say I want to change the property on the first row from "round" to "square"
UPDATE TB
SET my_json = parse_json('{ "FruitShape":"square", "FruitSize":55 }')
WHERE TB_ID = 1;
Is this what I am supposed to do?

Answer 1

You should not try to update, just append a new row and then use a view to access the current values.

Answer 2

You can do it with a javascript UDF. For example:
create or replace function merge_objects("a" object, "b" object)
returns object
language javascript
as
$$
return {...a, ...b}
$$;
And call like this:
select merge_objects(
object_construct('a',1,'b',2),
object_construct('b',3,'c',4)
);
select merge_objects(
parse_json('{"a":1,"b":[1,2,3]}')::object,
parse_json('{"c":2,"b":[2,3,4]}')::object
);