On 5/18/23 06:17, Brian Mendoza wrote:
Hello,
I have encountered unanticipated behaviour with a JSONB operator, and
wanted to make sure I am not misunderstanding its intended use.
When using the @> operator, I get this result.
select '{"a": [1]}'::jsonb @> '{"a": []}'::jsonb;
?column?
----------
t
(1 row)
However, given the phrasing in the documentation, I would have expected
False.
"Does the left JSON value contain the right JSON path/value entries at
the top level?"
Particularly given the following:
select '[1]'::jsonb = '[]'::jsonb;
?column?
----------
f
(1 row)
So the keys are the same, the values (when compared directly) are not,
but @> returns True. Have I misunderstood the usage of the operator?
The above queries have been run on postgres 14, if that helps.
Have you looked at the containment examples?:
https://www.postgresql.org/docs/current/datatype-json.html#JSON-CONTAINMENT
I'm thinking this:
-- A top-level key and an empty object is contained:
SELECT '{"foo": {"bar": "baz"}}'::jsonb @> '{"foo": {}}'::jsonb;
and/or this
"The general principle is that the contained object must match the
containing object as to structure and data contents, possibly after
discarding some non-matching array elements or object key/value pairs
from the containing object. "
applies.
--
Brian Mendoza
brian@xxxxxxxxxxx <mailto:brian@xxxxxxxxxxx>
Rotamap
www.rotamap.net <https://www.rotamap.net>
020 7631 1555
3 Tottenham Street London W1T 2AF
Registered in England No. 04551928
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
