警告：mysqli_stmt::bind_result()：绑定变量的数量与准备好的语句错误中的字段数量不匹配

Question

我有一个 mysql 查询，我正在将其转换为 mysqli（准备好的语句），但我遇到了一个引发以下错误的问题，

警告：mysqli_stmt::bind_result()：绑定变量的数量与准备好的语句中的字段数量不匹配

Mysql代码

$random_name_generated = vpb_generate_random_name().'.jpg'; //Generated name for uploaded files or images

if (move_uploaded_file($_FILES['file_to_upload']['tmp_name'], $final_uploads_location)) {
    $check_empty_field = mysql_query("select * from `vpb_uploads` where `username` = '".mysql_real_escape_string(strip_tags($username))."'  and `firstname` = '".mysql_real_escape_string("")."' and `lastname` = '".mysql_real_escape_string("")."'");
    if (mysql_num_rows($check_empty_field) < 1) {
        mysql_query("insert into `vpb_uploads` values('', '".mysql_real_escape_string($username)."', '', '', '".mysql_real_escape_string($random_name_generated)."', '', '', '', '', '".mysql_real_escape_string(date("d-m-Y"))."')");

        $identity = "image_one";
    } else {
        $get_empty_field = mysql_fetch_array($check_empty_field);
        $image_one = strip_tags($get_empty_field["image_one"]);
        $image_two = strip_tags($get_empty_field["image_two"]);
        $image_three = strip_tags($get_empty_field["image_three"]);
        $image_four = strip_tags($get_empty_field["image_four"]);
        $image_five = strip_tags($get_empty_field["image_five"]);
        global $identity;

以下是我尝试过的，即使它不起作用。我已经知道它不会起作用，但我想在问问题之前自己尝试一下。错误来自$get_empty_field = $stmt->bind_result($stmt);

if (move_uploaded_file($_FILES['file_to_upload']['tmp_name'], $final_uploads_location)) {
    $firstname = '""';
    $lastname = '""';
    $stmt = $mysqli->prepare("select * from `vpb_uploads` where `username` = ?  and `firstname` = ? and `lastname` = ?");
    $stmt->bind_param('sss', $username, $firstname, $lastname);
    $stmt->execute();
    $stmt->store_result();
    if ($stmt->num_rows < 1) {
        $date = 'date("d-m-Y")';
        $image_2 = "''";
        $image_3 = "''";
        $image_4 = "''";
        $image_5 = "''";
        $stmt = $mysqli->prepare("insert into `vpb_uploads` (`username`, `firstname`, `lastname`, `image_one`, `image_two`, `image_three`, `image_four`, `image_five`, `date`) values(?,?,?,?,?,?,?,?,?)");
        $stmt->bind_param('sssssssss', $username, $firstname, $lastname, $random_name_generated, $image_2, $image_3, $image_4, $image_5, $date);
        $stmt->execute();
        $stmt->close();

        $identity = "image_one";
    } else {
        $get_empty_field = $stmt->bind_result($stmt);
        $image_one = strip_tags($get_empty_field["image_one"]);
        $image_two = strip_tags($get_empty_field["image_two"]);
        $image_three = strip_tags($get_empty_field["image_three"]);
        $image_four = strip_tags($get_empty_field["image_four"]);
        $image_five = strip_tags($get_empty_field["image_five"]);
        global $identity;

Answer 1

你需要改变

$get_empty_field = $stmt->bind_result($stmt);

到

$get_empty_field = $stmt->bind_result($field1, $field2, $field3);

$fieldx 变量的数量等于所选字段的数量。如果你不知道有多少，使用这个：

  // Throw an exception if the result metadata cannot be retrieved
  if (!$meta = $stmt->result_metadata())
  {
    throw new Exception($stmt->error);
  }

  // The data array
  $data = array();

  // The references array
  $refs = array();

  // Iterate over the fields and set a reference
  while ($name = $meta->fetch_field())
  {
    $refs[] =& $data[$name->name];
  }

  // Free the metadata result
  $meta->free_result();

  // Throw an exception if the result cannot be bound
  if (!call_user_func_array(array($stmt, 'bind_result'), $refs))
  {
    throw new Exception($stmt->error);
  }

然后您在获取后使用$data['field'] 访问结果；