title: Emoji character () is not working with utf8mb4_bin in MySQL version 5.6
body: <p>I am trying to save emoji symbol to database record but each time it's not saving properly. 
  I've referred this <a href="https://stackoverflow.com/questions/39463134/how-to-store-emoji-character-in-my-sql-database">How to store Emoji Character in My SQL Database</a> but still not working.<br>
  As per solution on above question, I tried to change the character set from utf8 to utf8mb4 and collation from utf8mb4_bin. <br><br>
  I tried everything like resetting to default and then changing it in the database table. I tried utf8mb4_unicode_ci, utf8_unicode_ci and utf8mb4_bin but it's not working. <br><br>
  I am using MySQL 5.6 version. And I am changing the collation with below query<br></p>
  
  <pre><code>alter table `users` convert to character set utf8mb4 collate utf8mb4_bin;
  </code></pre>
  
  <p>The above code is working fine, it's changing the UTF type in database. But emoji is not saving properly it's saving as question marks (????)
  <br><br>
  <strong>Below is my database table structure example:</strong> </p>
  
  <pre><code>CREATE TABLE IF NOT EXISTS `users` (
    `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'System generated id used for uniqueness',
    `introduction` longtext COLLATE utf8mb4_bin,
    `other_details` longtext COLLATE utf8mb4_bin,    
     PRIMARY KEY (`id`),
   ) ENGINE=InnoDB  DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin AUTO_INCREMENT=41213 ;
  </code></pre>
  
  <p><br>
  <strong>To save emoji using below PHP code:</strong> <br></p>
  
  <pre><code>$dom = new DOMDocument('1.0', 'UTF-8');
  $strWithEmoji = "";
  $fullContent = '&lt;meta http-equiv="content-type" content="text/html; charset=utf-8"&gt;'
                 + $strWithEmoji;
  $this-&gt;save($fullContent); // Function for saving into database
  </code></pre>
  
  <p><br>
  I don't know exact how many bytes are storing but I am trying to save only 
  this emoji character "" and it's storing it as 4 question marks (????).<br></p>
  
  <p>I tried all solutions from below links, but didn't worked for me:<br>
  <a href="https://stackoverflow.com/questions/39463134/how-to-store-emoji-character-in-my-sql-database">How to store Emoji Character in My SQL Database</a>
  <br>
  <a href="https://stackoverflow.com/questions/279170/utf-8-all-the-way-through">UTF-8 all the way through</a>
  <br>
  <a href="https://stackoverflow.com/questions/34637105/the-ultimate-emoji-encoding-scheme">The ultimate emoji encoding scheme</a></p>