#1273 - Unknown collation: 'utf8mb4_unicode_ci' cPanel
The technique in this post worked for me
1) Click the "Export" tab for the database
2) Click the "Custom" radio button
3) Go the section titled "Format-specific options" and change the dropdown for "Database system or older MySQL server to maximize output compatibility with:" from NONE to MYSQL40.
4) Scroll to the bottom and click "GO".
I'm not certain if doing this causes any data loss, however in the one time I've tried it I did not notice any. Neither did anyone who responded in the forums linked to above.
Edit 8/12/16 - I believe exporting a database in this way causes me to lose data saved in Black Studio TinyMCE Visual Editor widgets, though I haven't ran multiple tests to confirm.
If you have already exported a .sql file, the best thing to do is to Find and Replace the following if you have them in your file:
utf8mb4_0900_ai_citoutf8_unicode_ciutf8mb4toutf8utf8_unicode_520_citoutf8_unicode_ci
It will replace utf8mb4_unicode_ci to utf8_unicode_ci. Now you go to your phpMyAdmin cPanel and set the DB collation to utf8_unicode_ci through Operations > Collation.
If you are exporting to a .sql, it's better to change the format on how you're exporting the file. Check out Evster's anwer (it's in the same page as this)
I had the same issue as all of our servers run older versions of MySQL. This can be solved by running a PHP script. Save this code to a file and run it entering the database name, user and password and it'll change the collation from utf8mb4/utf8mb4_unicode_ci to utf8/utf8_general_ci
<!DOCTYPE html><html><head> <title>DB-Convert</title> <style> body { font-family:"Courier New", Courier, monospace; } </style></head><body><h1>Convert your Database to utf8_general_ci!</h1><form action="db-convert.php" method="post"> dbname: <input type="text" name="dbname"><br> dbuser: <input type="text" name="dbuser"><br> dbpass: <input type="text" name="dbpassword"><br> <input type="submit"></form></body></html><?phpif ($_POST) { $dbname = $_POST['dbname']; $dbuser = $_POST['dbuser']; $dbpassword = $_POST['dbpassword']; $con = mysql_connect('localhost',$dbuser,$dbpassword); if(!$con) { echo "Cannot connect to the database ";die();} mysql_select_db($dbname); $result=mysql_query('show tables'); while($tables = mysql_fetch_array($result)) { foreach ($tables as $key => $value) { mysql_query("ALTER TABLE $value CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci"); }} echo "<script>alert('The collation of your database has been successfully changed!');</script>";}?>