postgres to json object

In postgresql I have a table named info that has columns like so:

kod_id, region

I need to get a json response like this:

"List of regions: [
            {
                "Region name": "Moscow region",
                "Region Code": "77"
            },
            {
                "Region Name": "Belgorod Oblast",
                "Region Code": "31"
            },
            {
                "Region Name": "Bryansk Oblast",
                "Region Code": "32"
            },
            {
                "Region Name": "Vladimir Oblast", 
                                "Region Code": "33"  
            }
        ]

I wrote a query of the form:

SELECT json_build_object('List of regions' , json_build_array ('Region name', 'region', 'region', 'region code', 'kod_id') ) FROM "regions"

and got the output:

{ "List of regions" : ["Region name", "Republic of Bashkortostan", "Region code", " 02"]}
{ "List of regions" : ["Region Name", "Republic of Buryatia", "Region Code", "03"]}
{ "List of Regions" : ["Region Name", "Republic of Altai", "Region Code", "04"]}
{ "List of Regions" : ["Region Name", "Republic of Dagestan", "Region Code", "05"]}
{ "List of Regions" : ["Region Name", "Republic of Ingushetia", "Region Code", "06"]}
{ "List of Regions" : ["Region Name", "Kabardino-Balkarian Republic", "Region Code", "07"]}

Can you tell me how to get the right answer?

>Solution :

Assuming you have this data :

create table regions (
  region varchar(20),
  kod_id int
);

insert into regions values
('Moscow region', 77),
('Belgorod Oblast', 31),
('Bryansk Oblast', 32),
('Vladimir Oblast', 33);

You will need to aggregates JSON objects built by json_build_object, as a JSON array using json_agg :

SELECT json_build_object('List of regions',
                            json_agg(
                               json_build_object ('Region name', region, 'region code', kod_id)
                            )
                        )
FROM regions;

Result :

{
   "List of regions":[
      {
         "Region name":"Moscow region",
         "region code":77
      },
      {
         "Region name":"Belgorod Oblast",
         "region code":31
      },
      {
         "Region name":"Bryansk Oblast",
         "region code":32
      },
      {
         "Region name":"Vladimir Oblast",
         "region code":33
      }
   ]
}

Demo here