Postgresql: select rows by OR condition - including going through json array - sql

Question

I have a table created by following query:
create table data
(
id integer not null unique,
owner text,
users jsonb not null
);
The table looks like this:
+----+-------+---------------------------------------------+
| id | owner | users |
+----+-------+---------------------------------------------+
| 1 | alice | [] |
| 2 | bob | [{"accountId": "alice", "role": "manager"}] |
| 3 | john | [{"accounId": "bob", "role": "guest"}] |
+----+-------+---------------------------------------------+
I need to get rows 1 and 2 on behalf of Alice.
Getting owner-based rows works perfect:
SELECT *
FROM data
WHERE owner = 'alice'
Getting jsonb-based rows is a little trickier though managable:
SELECT *
FROM data, jsonb_array_elements(users) x
WHERE (x ->> 'accountId') = 'alice'
But getting them together gets me just the jsonb-based ones:
SELECT *
FROM data, jsonb_array_elements(users) x
WHERE owner = 'alice' OR (x ->> 'accountId') = 'alice'
How do I get the selection that looks like following?
+----+-------+---------------------------------------------+
| id | owner | users |
+----+-------+---------------------------------------------+
| 1 | alice | [] |
| 2 | bob | [{"accountId": "alice", "role": "manager"}] |
+----+-------+---------------------------------------------+
Even better if I can get a selection that looks like this
+----+----------+
| id | role |
+----+----------+
| 1 | owner |
| 2 | manager |
+----+----------+

Answer 1

The problem is with the empty json array, which evicts the corresponding row from the result set when cross joined with jsonb_array_elements(). Instead, you can make a left join lateral:
select d.*
from data d
left join lateral jsonb_array_elements(d.users) as x(js) on 1 = 1
where 'alice' in (d.owner, x.js ->> 'accountId')
Note that, if your array always contains 0 or 1 element, tyou don't need the lateral join - your query would be simpler phrased as:
select d.*
from data d
where 'alice' in (d.owner, d.data -> 0 ->> 'accountId')
Demo on DB Fiddle - both queries return:
id | owner | users
-: | :---- | :------------------------------------------
1 | alice | []
2 | bob | [{"role": "manager", "accountId": "alice"}]