How do I update a JSON field in PostgreSQL? - sql

Question

I have a table with a column called data that contains some JSON. If the data column for any given row in the table is not null, it will contain a JSON-encoded object with a key called companyDescription. The value associated with companyDescription is an arbitrary JavaScript object.
If I query my table like this
select data->>'companyDescription' from companies where data is not null;
I get rows like this
{"ops":[{"insert":"\n"}]}
I am trying to update all rows in the table so that the companyDescription values will be wrapped in another JSON-encoded JavaScript object in the following manner:
{"type":"quill","content":{"ops":[{"insert":"\n"}]}}
Here's what I have tried, but I think it won't work because the ->> operator is for selecting some JSON field as text, and indeed it fails with a syntax error.
update companies
set data->>'companyDescription' = CONCAT(
'{"type":"quill","content":',
(select data->>'companyDescription' from companies),
'}'
);
What is the correct way to do this?

Answer 1

You can use a function jsonb_set. Currently XML or JSON values are immutable. You cannot to update some parts of these values. You can replace these values by some new modified value.
postgres=# select * from test;
┌──────────────────────────────────────────────────────────────────────┐
│ v │
╞══════════════════════════════════════════════════════════════════════╡
│ {"companyId": 10, "companyDescription": {"ops": [{"insert": "\n"}]}} │
└──────────────────────────────────────────────────────────────────────┘
(1 row)
postgres=# select jsonb_build_object('type', 'quill', 'content', v->'companyDescription') from test;
┌───────────────────────────────────────────────────────────┐
│ jsonb_build_object │
╞═══════════════════════════════════════════════════════════╡
│ {"type": "quill", "content": {"ops": [{"insert": "\n"}]}} │
└───────────────────────────────────────────────────────────┘
(1 row)
postgres=# select jsonb_set(v, ARRAY['companyDescription'], jsonb_build_object('type', 'quill', 'content', v->'companyDescription')) from test;
┌────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ jsonb_set │
╞════════════════════════════════════════════════════════════════════════════════════════════════════╡
│ {"companyId": 10, "companyDescription": {"type": "quill", "content": {"ops": [{"insert": "\n"}]}}} │
└────────────────────────────────────────────────────────────────────────────────────────────────────┘
(1 row)
So you final statement can looks like:
update companies
set data = jsonb_set(data::jsonb,
ARRAY['companyDescription'],
jsonb_build_object('type', 'quill',
'content', data->'companyDescription'))
where data is not null;