Unexpected behavior of jsonb_set() with a `null` value
Dear Support Team,
With `jsonb_set()`, when `new_value` is `NULL`, the function would **erase
the whole object**:
postgres=# SELECT jsonb_set('{"something":1}'::jsonb, '{language}', null,
true);
jsonb_set
-----------
(1 row)
This is really dangerous for it may lead to data loss. Imaging the `
new_value` argument being a function which returns `NULL` values in some
cases.
The expected behavior is, perhaps, to convert an SQL `NULL` value to JSONB
null value: 'null'::jsonb
This way no data would be lost.
Or at the very least, this behavior should be documented.
Thank you in advance,
Mark
Марк schrieb am 12.09.2019 um 12:55:
With `jsonb_set()`, when `new_value` is `NULL`, the function would **erase the whole object**:
postgres=# SELECT jsonb_set('{"something":1}'::jsonb, '{language}', null, true);
jsonb_set
-----------
(1 row)This is really dangerous for it may lead to data loss. Imaging the `new_value` argument being a function which returns `NULL` values in some cases.
The expected behavior is, perhaps, to convert an SQL `NULL` value to JSONB null value: 'null'::jsonb
This way no data would be lost.Or at the very least, this behavior should be documented.
I have asked the same: /messages/by-id/qfkua9$2q0e$1@blaine.gmane.org
In short: not a bug ;)
Thomas Kellerer <spam_eater@gmx.net> writes:
Марк schrieb am 12.09.2019 um 12:55:
The expected behavior is, perhaps, to convert an SQL `NULL` value to JSONB null value: 'null'::jsonb
I have asked the same: /messages/by-id/qfkua9$2q0e$1@blaine.gmane.org
There are other more-apropos threads in the archives, though I'm too
lazy to go find them right now. IMO the problem here is an assumption
that SQL NULL should be interchangeable with a JSON NULL. It's not,
and we don't intend to make it so, because (a) the definitional quagmire
that would result is bottomless; (b) people asking for this are generally
trying to use SQL NULL as a live data value, which is almost always just
a bad idea.
regards, tom lane