如何检查行中是否存在ID，如果不存在则回显一些文本[关闭]

Question

I'm using the following to select some photo, how do I incorporate 'IF EXISTS' so i can echo some text if no ID is found.

$Result = mysql_query("SELECT * FROM photos WHERE UID = '$ID' limit 30")

Answer 1

if (mysql_num_rows($Result)) echo "You have photos!";
else echo "Dude... take some photos!";