foreach($res as $key) {
    echo $key['id'].'<br>';
    $sql= "INSERT INTO Post VALUES('".$key['id']."')";
    if (mysql_query($sql) == TRUE) {
        echo "New record created successfully";
    } else {
        echo "Error: " . $sql . "<br>" . $link->error;
    }
}
For the first entry it works and adds it to the database but after that it gives the following error : Trying to get property of non-object
print_r($res) gives the following output :
Array
(
    [0] => Array
        (
            [message] =>*******
            [created_time] => DateTime Object
                (
                    [date] => 2016-01-13 20:14:32.000000
                    [timezone_type] => 1
                    [timezone] => +00:00
                )
            [id] => 1413366785545501_1686416964907147
        )
    [1] => Array
        (
            [message] =>*****
            [created_time] => DateTime Object
                (
                    [date] => 2015-11-27 15:51:16.000000
                    [timezone_type] => 1
                    [timezone] => +00:00
                )
            [id] => 1413366785545501_1674032329478944
        )
    [2] => Array
        (
            [message] => The 'AD- MAD' competition :)
            [story] => KRITA // Chalk your art. added 4 new photos.
            [created_time] => DateTime Object
                (
                    [date] => 2015-10-07 19:02:12.000000
                    [timezone_type] => 1
                    [timezone] => +00:00
                )
            [id] => 1413366785545501_1662706990611478
        )
    [3] => Array
        (
            [message] => *****
            [story] => KRITA // Chalk your art. created a poll.
            [created_time] => DateTime Object
                (
                    [date] => 2015-10-02 21:06:05.000000
                    [timezone_type] => 1
                    [timezone] => +00:00
                )
            [id] => 1413366785545501_1661659277382916
        )
I just want to store the id's in the database
 
    