How to update objects in a JSON array based on a specific key/value pair in Postgres

Question

I have data that looks like this:

id  name    blocks
1   Test 1  [{"name": "Bob", "type": "INFO", "title": "CFO"}, {"type": "FOOTER"}]
2   Another [{"name": "Bob", "type": "INFO", "title": "Manager"}, {"type": "FOOTER"}]
3   Final   [{"id": 22, "type": "IMAGE"}]

The user may want to change their name across all rows, so I'd need to have a Postgres JSON version of:

UPDATE blocks SET name = 'New Name' WHERE type = 'INFO';

How do I write a query that will search these arrays of objects for a specific type key of value "INFO" ? The big catch here is that these objects can be in any order in the array. So the INFO block isn't always necessarily at index 0.

Answer 1

There are 2 name fields in your example.

If you want to update the name tag in the json field with your condition then try below query:

with cte as 
(
select 
id,
name,
json_agg(case when t.x->>'type'='INFO' then jsonb_set(t.x,'{name}','"New Name"',false) else t.x end) "new_value"
from blocks cross join lateral jsonb_array_elements(blocks::jsonb) t(x)
group by 1,2
)
update blocks t1 
set blocks=t2.new_value
from cte t2 
where t1.id=t2.id;

DEMO

If you want to update the name field of your table with your condition then try below query:

with cte as 
(
select 
id,
name,
bool_or(t.x->>'type'='INFO') "new_value"
from blocks cross join lateral jsonb_array_elements(blocks::jsonb) t(x)
group by 1,2
)
update blocks t1 
set name='New Name'
from cte t2 
where t1.id=t2.id and t2.new_value=true;

DEMO

Answer 2

This is ultimately what I went with (based on the accepted answer), just cleaned up a bit and named using the real table names & JSONB structure. This also makes sure a user can only mass-update their own data, not someone else's.

WITH new_data AS (
  SELECT id, json_agg(
    CASE
      WHEN blocks.block->>'type' = 'CONTACT_INFO'
        THEN jsonb_set(blocks.block, '{data, name}', '"New Name"', false)
      ELSE
        blocks.block
    END) AS new_block
  FROM reels
  CROSS JOIN LATERAL jsonb_array_elements(blocks) blocks(block)
  WHERE owner_id = '9292dcc6-f906-418a-aee0-074b297bfb52'
  GROUP BY id
)
UPDATE reels
SET blocks = new_data.new_block
FROM new_data
WHERE reels.id = new_data.id;