postgres_camelize_functions.sql

create or replace function camelize(text)
returns text as $$
declare parts text[] = string_to_array($1, '_');
declare capitalized_parts text[] = (select array_agg(initcap(n)) from unnest(parts) as n);
begin
    return parts[1] || array_to_string(capitalized_parts[2:], '');
end;
$$ language plpgsql;

create or replace function camelize_keys(json)
returns json as $$
declare i text;
declare x jsonb = '{}'::jsonb;
begin
    for i in (select * from json_object_keys($1)) loop
        x = jsonb_set(x, ARRAY[camelize(i)], ($1->i)::jsonb);
    end loop;

    return to_json(x);
end;
$$ language plpgsql;

create or replace function jsonb_camelize_keys(jsonb)
returns json as $$
begin
    return camelize_keys(to_json($1));
end;
$$ language plpgsql;

create or replace function camelize_array(json) returns json as $$
declare i json;
declare x json[];
begin
    for i in (select * from json_array_elements($1)) loop
        x = array_append(x, camelize_keys(i));
    end loop;
    
    return to_json(x);
end;
$$ language plpgsql;