如何使用php 5.5.17(如谷歌图表中的JSON)对postgres9.5的结果进行数组

header('Content-Type: application/json; charset=utf-8'); 

$db = pg_connect("host=localhost port=5432 dbname=postgres user=postgres password=bla"); 
$result = pg_query($db,"SELECT kv.ph, kv.broj FROM public.kv ORDER BY date DESC LIMIT 5"); 

while ($row = pg_fetch_object($result)) { 
    echo json_encode($row),','; 
} 

pg_close($db); 
header('Content-Type: application/json; charset