Today's gasoline is already loaded up with all the additives that one is likely to need on a regular basis.  There really isn't anything you should be adding "just because".  Certain additives can be helpful if problems crop up though.

What kind of gasoline additives will help maintain the engine efficiency/life?
In my table I have a field "firstname" and a field "lastname". I would like to select all records where firstname + space + lastname is a certain value.

I've tried this:

$sql = "SELECT * FROM sam_users WHERE (user_firstname + ' ' + user_lastname LIKE ?)";


But this isn't working. With Google I've found something about using ||, but I don't really understand how I should use that operator. Note that I don't want to use an or-operator (what || is in many languages), but something to concatenate 2 fields (with a space between them) and using a LIKE on that.

Thanks!
