Mysqli编写语句寄存器

Question

好的，我有一个问题。我需要检查用户是否已经存在，但问题是现在我需要在if()中输入我无法获取，因为我已经关闭，但如果我没有关闭，我得到一个错误，因为无法运行2条语句。所以我想如果有人能帮助我？我有其他代码，但我只在这里给代码。

这里是我的代码：

$result = $mysqli->prepare("SELECT username FROM user WHERE username=?"); 
$result->bind_param("s", $username); 
$result->execute(); 
$result->bind_result($username);         
$result->close(); 

if(){ 
$register = $mysqli->prepare("INSERT INTO user 
        (username, password, email, rr, rank) 
        VALUES (?, ?, ?, ?, ?)"); 
$register->bind_param("sssii", $username, $kode, $email, $rr, $rank); 
$register->execute(); 
$register->close();         
} else { 
    echo "User already exists!"; 
} 

Answer 1

更新： “！用户已经存在” 更符合逻辑的说法

$result = $mysqli->prepare("SELECT username FROM user WHERE username=?"); 
$result->bind_param("s", $username); 
$result->execute(); 
$found = $result->fetch();       
$result->close(); 

if ($found){   
    echo "User already exists!";           
} else { 
    $register = $mysqli->prepare("INSERT INTO user 
        (username, password, email, rr, rank) 
        VALUES (?, ?, ?, ?, ?)"); 
    $register->bind_param("sssii", $username, $kode, $email, $rr, $rank); 
    $register->execute(); 
    $register->close(); 

}