$selectTip = $pdo->query("SELECT * FROM `tips_rate`
WHERE `tip_id` = '".$row['id']."' "
);
$selecttotal = mysqli_num_rows($selectTip);
$rate = $pdo->query("SELECT SUM(star) as startotal FROM `tips_rate`
WHERE `tip_id` = '".$row['id']."' "
);
$startotal = mysqli_fetch_array($rate);
echo $startotal['startotal']/$selecttotal;
當我echo他們互除以的結(jié)果後假設(shè)沒有值他會出現(xiàn)NAN...能不能顯示 0？
php mariadb sum除以若沒有值，會出現(xiàn)NAN，能否顯示0？
慕尼黑5688855
2019-03-18 15:34:03
