Updating JSON column in Postgres? - postgresql

Question

I've got a JSON column in Postgres, that contains data in the following structure
{
"listings": [{
"id": "KTyneMdrAhAEKyC9Aylf",
"active": true
},
{
"id": "ZcjK9M4tuwhWWdK8WcfX",
"active": false
}
]
}
I need to do a few things, all of which I am unsure how to do
Add a new object to the listings array
Remove an object from the listings array based on its id
Update an object in the listings array based on its id
I am also using Sequelize if there are any built in functions to do this (I can't see anything obvious)

Answer 1

demo:db<>fiddle
Insert (jsonb_insert()):
UPDATE mytable
SET mydata = jsonb_insert(mydata, '{listings, 0}', '{"id":"foo", "active":true}');
Update (expand array, change value with jsonb_set(), reaggregate):
UPDATE mytable
SET mydata = jsonb_set(mydata, '{listings}', s.a)
FROM
(
SELECT
jsonb_agg(
CASE WHEN elems ->> 'id' = 'foo' THEN jsonb_set(elems, '{active}', 'false')
ELSE elems
END
) as a
FROM
mytable,
jsonb_array_elements(mydata -> 'listings') AS elems
) s;
Delete (expand array, filter relevant elements, reaggregate):
UPDATE mytable
SET mydata = jsonb_set(mydata, '{listings}', s.a)
FROM
(
SELECT
jsonb_agg(elems) as a
FROM
mytable,
jsonb_array_elements(mydata -> 'listings') AS elems
WHERE elems ->> 'id' != 'foo'
) s;
Updating and deleting can be done in one line like the inserting. But in that case you have to use the array element index instead of a certain value. If you want to change an array element with a value you need to read it first. This is only possible with a prior expanding.