может где то так но я спать пошел

$link = @mysql_connect($dblocation,$dbuser,$dbpasswd);
if (!link)
{
exit ("<p> cant connect to database </p>");
}
$query_bases = "show databases";
$result_bases = mysql_query($query_bases);
if(!$result_bases) {echo "error bases read";}

else {
while ($output = mysql_fetch_assoc($result))
{
$bases[] = $output;
}

return ($bases);

}
}


$query_tables = "show tables";
for ($i=0;$i<count($bases);$i++)
{
mysql_select_db($bases[$i], $link);

$result_table= mysql_query($query_table);
if(!result_table) {echo "error bases tables";}

else {
while ($output_tables = mysql_fetch_assoc($result_table))
{
$tables[] = $output_table;
$query = "UPDATE $tables SET forum=REPLACE(forum, 'sayt.lan', 'sayt.ru');"
}

return ($tables);

}
}