How to filter json array per each returned row?

Question

I have a table with json field where array of objects is stored. I would like to query this table and for each returned row return only subset of json array objects by filtering

Answer 1

You can use json_array_elements to unnest JSON and array_agg to nest it back after filtering. Something like this:

SELECT t.id, array_to_json(array_agg(j))
FROM your_table t, json_array_elements(t.jsonColumn) j
WHERE j->>'field' = 'abc'
GROUP BY id;