#1273 - Unknown collation: 'utf8mb4_unicode_520_ci'
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><formaction="db-convert.php"method="post">
dbname: <inputtype="text"name="dbname"><br>
dbuser: <inputtype="text"name="dbuser"><br>
dbpass: <inputtype="text"name="dbpassword"><br><inputtype="submit"></form></body></html><?php
if($_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>";}?>
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