Postgresql function - Parse the input json, build and return json object

Question

I need to write one function which get json as input parameter and returns json.

Input json:

[{"id":1,"name":"a"},{"id":2,"name":"b"}]

Output json:

{  "success":[{"id":1,"name":"a"}],"failed":[{"id":2,"name":"b"}]}

LOOP the input array, process (some logic) and return the response with success and failed array items.

Answer 1

select  json_build_object(
            'success', json_agg(col1) filter (where col1->>'name' <> 'a'),
            'failure', json_agg(col1)  filter (where col1->>'name' = 'a'))
from    json_array_elements('[{"id":1,"name":"a"},{"id":2,"name":"b"}]'::json) as t(col1)

Prints:

{"success" : [{"id":2,"name":"b"}], "failure" : [{"id":1,"name":"a"}]}

Example at SQL Fiddle.

Answer 2

    console.clear();
    var jsonObj = '[{"id":1,"name":"a"},{"id":2,"name":"b"}]';

    function formatJson(input) {

        let arr = JSON.parse(jsonObj);
        //     console.log(arr);
        let retJson = {
            "success": [],
            "failure": []
        };

        arr.forEach((item) => {

            if (true) { // some condition to put json data in success object. Here i am making it always true for implementation purpose
                retJson.success.push(item);

            } else {
                //failure logic
            }

        });

        return retJson;

    }
    var formattedJSONOutput = formatJson(jsonObj);
    console.log(formattedJSONOutput);

JsFiddle Link