#1273 - Unknown collation: 'utf8mb4_unicode_ci'
Solution : 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>
<?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>";
}
?>
