Php序列化

mysql_fetch_array返回一个数组,因此您需要选择所需数组的位:

$row = mysql_fetch_array($query);

$data=unserialize($row['friends']);

你也应该养成检查错误的习惯,例如

$result = mysql_query("SELECT friends FROM users WHERE id='$myid'");
if ($result) 
{
    if ($row = mysql_fetch_array($result))
    {
         $data=unserialize($row['friends']);

    }
    else
    {
         //empty result, set up empty data?
         $data=array();
    }

} 
else 
{
    die('Invalid query: ' . mysql_error());
}