Hackers,
Most of the jsonpath methods auto-unwrap in lax mode:
david=# select jsonb_path_query('[-2,5]', '$.abs()');
jsonb_path_query
------------------
2
5
(2 rows)
The obvious exceptions are size() and type(), which apply directly to arrays, so no need to unwrap:
david=# select jsonb_path_query('[-2,5]', '$.size()');
jsonb_path_query
------------------
2
(1 row)
david=# select jsonb_path_query('[-2,5]', '$.type()');
jsonb_path_query
------------------
"array"
But what about string()? Is there some reason it doesn’t unwrap?
david=# select jsonb_path_query('[-2,5]', '$.string()');
ERROR: jsonpath item method .string() can only be applied to a bool, string, numeric, or datetime value
What I expect:
david=# select jsonb_path_query('[-2,5]', '$.string()');
jsonb_path_query
—————————
"2"
"5"
(2 rows)
However, I do see a test[1] for this behavior, so maybe there’s a reason for it?
Best,
David
[1]: https://github.com/postgres/postgres/blob/REL_17_BETA1/src/test/regress/expected/jsonb_jsonpath.out#L2527-L2530
