array_unique

[Gaijin]

It doesn't work because you're creating a new file db.htm make 1 & 2 every time an user visits your site.
You use file_put_contents wrong, try it this way.

PHP Code:

file_put_contents('Database.html', implode('', array_unique(array_merge($data1,$data2))), FILE_APPEND); 


http://www.php.net/manual/en/function.fi...ntents.php

edit: for a new line use \n inside of double qoutes.