现有用户的密码_hash [关闭]

I get a PHP Error and returning empty body on hurl.it. Im trying to hash the password of existing users in my DB.

using user_id as POST and update it to my DB in a new created column

// Create connection
$con = mysqli_connect($dbPath,$dbUserName,$dbPassword,$dbSchema);

// Check connection
if (mysqli_connect_errno()) {
  $error = "DB connection error";
}

$user_id = $_POST['user_id'];  


//exisitng password
$sql = mysqli_query($con, "SELECT password FROM user_table 
                            WHERE user_id = '$user_id'");

if(!$sql) $error = "SELECT user_table error";

$i=0;
while($result = mysqli_fetch_assoc($sql)){

    $hash[$i] = $result;

    if($hash[$i]) {
        $check_hash = password_hash($hash[$i], PASSWORD_DEFAULT);

        //store into DB
        $result2 = mysqli_query($con, "INSERT INTO user_table (password_secure) VALUES   ('$check_hash')"); 
    }
    $i++;
}



if(!$result2) $error = "INSERT user_table error";
// Set returns
if (!$error) $status = "successful";

There are many problems in your code, but the main culprit is the fact that you use INSERT when you should really be using UPDATE:

UPDATE user_table SET password_secure=? WHERE user_id=?

$result will be an array, because you're using mysqli_fetch_assoc() so you're trying to hash an array

$password = $result['password'];

if($password){
    $check_hash = password_hash($password, PASSWORD_DEFAULT);