Inserting html code in a mysql table

You should not need slashes. The only thing that will cause a problem during normal inserts is the quotes, and mysql_escape_string() should handle that excepting charset issues. Try mysql_real_escape_string() as well.

Also, note that storing raw user-supplied HTML in the database can lead to security issues. Consider using something like bbcode or markdown instead.

I prefer to convert code to ordinary string before inserting to database. I think, it's most safe scenario. Consider using this code:

$article_code = base64_encode($article_code);
/* insert to database */

So, when you want to use that code back, just decode using base64_decode. I suggest you to use 'text' data type for saving $article_code rather than 'varchar'.