Remove entire json object from JSON array - postgresql

Question

I'm trying to update the list of contacts by deleting whatever contact is requested to be deleted by user input. In other words, trying to remove an entire JSON object from a JSON array in my PostgreSQL database from a Node.js script, but I get error
error: null value in column "info" of relation "user_emails" violates
not-null constraint
I double-checked and the value and everything is there. When I try it here online it works, but on my server it returns the error. How can I fix this?
DROP table if exists user_emails;
CREATE table user_emails (
id serial not null PRIMARY KEY,
info jsonb NOT NULL
);
insert into user_emails(info) values('{
"userid": "4",
"mailbox": "johndoe#example.com",
"contacts": [
{
"id": "ghr3gk8dez4",
"email": "janedoe#gmail.com",
"last_name": "Doe",
"first_name": "Jane",
"date_created": "2022-05-08T20:52:47.967Z"
},
{
"id": "th2lypvoxpr1652045110763",
"email": "aldoe#gmail.com",
"last_name": "Doe",
"first_name": "Al",
"date_created": "2022-05-08T21:25:10.763Z"
},
{
"id": "ld123tqicmj1652045372671",
"email": "stdoe#gmail.com",
"last_name": "Doe",
"first_name": "Stella",
"date_created": "2022-05-08T21:29:32.671Z"
},
{
"id": "1ltbrpbj8xf1652045768004",
"email": "mdoe#mail.com",
"last_name": "Doe",
"first_name": "Marta",
"date_created": "2022-05-08T21:36:08.004Z"
},
{
"id": "1dgntfwvsmf1652045832589",
"email": "nala#mail.com",
"last_name": "La",
"first_name": "Na",
"date_created": "2022-05-08T21:37:12.589Z"
},
{
"id": "ll3z1n0jkhc1652045984538",
"email": "bdoe#mail.com",
"last_name": "doe",
"first_name": "bruno",
"date_created": "2022-05-08T21:39:44.538Z"
},
{
"id": "kzr996xxxt1652046050118",
"email": "pp#mail.com",
"last_name": "Perf",
"first_name": "Perf",
"date_created": "2022-05-08T21:40:50.118Z"
},
{
"id": "41bovnvsihq1652046121940",
"email": "mmd#mm.com",
"last_name": "Doe",
"first_name": "Melinda",
"date_created": "2022-05-08T21:42:01.940Z"
},
{
"id": "tnjlj4dcg2b1652046154937",
"email": "keke#j.com",
"last_name": "Kee",
"first_name": "Kee",
"date_created": "2022-05-08T21:42:34.937Z"
},
{
"id": "hor0wafkuj1652046684582",
"email": "jojo#mail.com",
"last_name": "Jo",
"first_name": "Jo",
"date_created": "2022-05-08T21:51:24.582Z"
}
],
"auto_reply": false,
"email_name": "johndoe",
"signatures": [],
"domain_name": "example.com",
"date_created": "2022-05-08T20:39:54.881Z",
"forward_email": [],
"auto_reply_messages": []
}');
this is my UPDATE
UPDATE user_emails SET info = (SELECT jsonb_agg(j)
FROM jsonb_array_elements(user_emails.info->'contacts') as t(j)
WHERE j ->> 'id' not in ('ghr3gk8dez4'));
SELECT * FROM user_emails;

Answer 1

jsonb_agg, like so many other aggregate functions, returns NULL if there are no rows to aggregate. You might be looking to COALESCE it to an empty array instead:
UPDATE user_emails
SET info = jsonb_set(
user_emails.info,
'{contacts}',
COALESCE(
(SELECT jsonb_agg(j)
FROM jsonb_array_elements(user_emails.info->'contacts') as t(j)
WHERE j ->> 'id' not in ('ghr3gk8dez4')
),
'[]'::jsonb
)
);

Answer 2

I don't think there is an efficient way to do that using only built-in functions.
There is an operator #- that removes an element by specifying the path, e.g. info #- '{contacts, 0}' would do what you want. However, it's not straight forward to build such a "path array" directly.
I would write a function that finds the index of the contact to be deleted and generates the path array:
create or replace function find_entry(p_info jsonb, p_id text)
returns text[]
as
$$
select array['contacts', (idx - 1)::text]
from jsonb_array_elements(p_info -> 'contacts') with ordinality as t(element, idx)
where t.element ->> 'id' = p_id
limit 1;
$$
language sql;
The -1 is necessary because SQL uses 1-based numbering, but in JSON arrays start at zero.
With that function you can then do:
update user_emails
set info #- find_entry(info, 'ghr3gk8dez4')
where ...