Mysql – Change the same field from all the tables from a particular database

If you have foreign keys to this table, add the option ON DELETE CASCADE. Then when you delete a row in a parent table all the rows in the child tables that refference that row will be deleted as well.

In order to change the collation for all of the tables in certain database you should create a custom script and execute it on the server.

Here is a sample PHP script:

<?php

$database_name='dbname';
$database_username='dbusername';
$database_password='dbpassword';

$connection = mysql_connect('localhost',$database_username,$database_password);

if(!$connection) {
    echo "Cannot connect to the database – incorrect details";
} else{
    mysql_select_db($database_name);
    $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 "Successfull collation change!"; 
}
?>