哪些錯誤與此準備好的聲明

Question

我有一份聲明中剛剛學到的幾個小時前，但我總是得到的回報0

$ip = $data 
$stmt = $mysqli->prepare("SELECT counter_ip 
          FROM counter_out 
          WHERE counter_ip = ?"); 
$stmt->bind_param('s', $ip); 
$stmt->execute; 
$stmt->bind_result($r_ip); 
$stmt->fetch(); 
echo "<pre>"; 
echo $r_ip; 
echo "</pre>"; 

bind_result我嘗試了所有IDBS， 但是，當我做沒有準備好的聲明中這樣它的工作原理

$sql = "SELECT counter_ip 
       FROM counter_out 
      WHERE counter_ip = '$ip'"; 
$result = $mysqli->query($sql); 
$dupecheck = $result->fetch_assoc(); 
echo "<pre>"; 
echo $dupecheck[counter_ip]; 
echo "</pre>"; 

準備好的聲明中有錯誤嗎？

Answer 1

$stmt->execute; 

這是一種方法。它應該是：

$stmt->execute(); 

Answer 2

$mysqli->prepare("SELECT counter_ip FROM counter_out WHERE counter_ip = :s");