PHP/MySql - DateTime 检测是否已分配值？

Question

我想创建一个仅在日期时间值不为空时运行的 if 语句 (0000-00-00 00:00:00)

我已通过查询将值传递给变量，但如何确定它是否等于 0000-00-00 00:00:00？

$query = "SELECT * FROM stats WHERE member_id='" . $_SESSION['SESS_MEMBER_ID'] . "' "; 
$result = mysql_query($query);

while($row = mysql_fetch_array($result, MYSQL_ASSOC)) 
{
  $money = $row['money'];
  $bank_money = $row['bank_money'];
  $ap = $row['ap'];
  $exp = $row['exp']; 
  $last_ap_update = $row['last_ap_update'];
} 

if ($last_ap_update != ){ //Can i verify its NULL-ness here so i can run this if stament or run else?
}

Answer 1

为什么不直接比较呢:

if ($last_ap_update != "0000-00-00 00:00:00")
{
      //do whatever.
}