检查mysql用户存在

Question

$check="SELECT * FROM users WHERE name = '$_POST[name]'"; 
$rs = mysqli_query($conn,$check); 
$data = mysqli_fetch_array($rs, MYSQLI_NUM); 
if($data[0] > 1) { 
    echo "User Already in Exists<br/>"; 
}else 
    echo "User does Not exist"; 

这是正确的方法是什么？它说用户不存在，不管是什么;并且我知道在db中有一个名为“test”的用户。

Answer 1

// this line makes mysqli throw exceptions so you'll never have to check 
// return values for false 
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); 

// prepare a statement checking for existence 
$stmt = $conn->prepare('SELECT 1 FROM users WHERE name = ?'); 

// bind the POST param to the parameter 
$stmt->bind_param('s', $_POST['name']); 
$stmt->execute(); 

// if there are any rows, that means the name exists 
if ($stmt->fetch()) { 
    echo 'User "', htmlspecialchars($_POST['name']), '" already exists<br/>'; 
} else { 
    echo 'User "', htmlspecialchars($_POST['name']), '" does not exist<br/>'; 
}