php - Unable to update column with appropriate charset -

i'm experiencing huge issue encoding , more entries go in database. when insert data, characters displayed properly. however, when try update column, characters misread 1 of these: авдвадва. in same time, when insert new rows, data looks in phpmyadmin: Кон.

<form action="additem.php" method="post">     <p>         <label class='title' for="title"> title</label>         <input type="text" name="title" id="title" class="input"/>     </p>      <p>         <label class='description' for="description"> description</label>         <textarea name="description" id="description" rows="10" cols="35"></textarea>     </p>          <p>         <input type="submit" class='buttono' name="addentry" id="addentry" value="add new entry" />     </p> </form> 

this db.php

<?php  class db {      public $mysql;      function __construct() {         $this->mysql = new mysqli('localhost', 'root', 'password', 'to-do') or die("unable connect database");     }      function delete_by_id($id) {         $query = "delete todo id = $id";         $result = $this->mysql->query($query) or die("there problem");     }      function update_by_id($id, $description) {         $query = "update todo                  set description = ?                  id = ?";           if ($stmt = $this->mysql->prepare($query)) {             $stmt->bind_param('si', $description, $id);             $stmt->execute();          }     }  } 

this additem.php

<?php  require 'db.php'; $db = new db();  if (isset($_post['addentry'])) {     $query = "insert todo values ('', ?, ?)";      if ($stmt = $db->mysql->prepare($query)) {         $stmt->bind_param('ss', $_post['title'], $_post['description']);         $stmt->execute();         header('location: index.php');     }  } else {     die ($db->mysql->error); } 

what's wrong it? tried setting charset utf-8 before query gets executed it's still same (actually seems not issue).

you must set mysql connection charset utf-8. can use $mysql->set_charset("utf8") this:

<?php  class db {      public $mysql;      function __construct() {       $this->mysql = new mysqli('localhost', 'root', 'password', 'to-do') or die("unable connect database");       if (!$this->mysql->set_charset("utf8")) {         throw new exception("error loading character set utf8: " .  $this->mysql->error);       }      }      function delete_by_id($id) {         $query = "delete todo id = $id";         $result = $this->mysql->query($query) or die("there problem");     }      function update_by_id($id, $description) {         $query = "update todo                  set description = ?                  id = ?";           if ($stmt = $this->mysql->prepare($query)) {             $stmt->bind_param('si', $description, $id);             $stmt->execute();          }     }  }