php - UNIX_TIMESTAMP(时间戳) 使用

Question

我正在尝试获取特定时间戳列的 unix_timestamp 值。但我很困惑。

$timecheck = mysql_query("SELECT UNIX_TIMESTAMP(datetime) FROM machine where m_id = $m_id");
                    if (mysql_num_rows($timecheck) > 0){
                        while ($timefetch = mysql_fetch_object($timecheck)) {
                            echo $timefetch->datetime;
                            print_r($timefetch[0]->datetime);
                            if (($timefetch->datetime - time()) > 6000){
                                echo "1";
                            }
                            else {
                                echo "0";
                            }
                            }

返回的时间戳值是一个 stdClass 对象。不能用它来比较。有人可以帮我用下面的代码吗

Answer 1

在 SQL 查询中为列名使用别名:

SELECT UNIX_TIMESTAMP(datetime) AS datetime FROM machine where m_id = $m_id