On 2024-06-12 We 16:02, David G. Johnston wrote:
On Sat, Jun 8, 2024 at 3:50 PM David E. Wheeler
<da...@justatheory.com> wrote:
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?
Adding Andrew.
I'm willing to call this an open item against this feature as I don't
see any documentation explaining that string() behaves differently
than the others.
Hmm. You might be right. Many of these items have this code, but the
string() branch does not:
if (unwrap && JsonbType(jb) == jbvArray)
return executeItemUnwrapTargetArray(cxt, jsp, jb, found,
false);
cheers
andrew
--
Andrew Dunstan
EDB:https://www.enterprisedb.com
