[PHP] 根據查MySQL有沒有結果執行不同程式碼

        $servername = "localhost";
        $username = "user";
        $password = "pass";
        $dbname = "dbname";
        // Create connection
        $conn = new mysqli($servername, $username, $password, $dbname);
        // Check connection
        if ($conn->connect_error) {
                die("Connection failed: " . $conn->connect_error);
        }

        $sql = "SELECT field FROM table where field = '1'";
        $result = $conn->query($sql);
        if($result->num_rows > 0){
                echo "0";
        }else{
                echo "1";
        }
?>