Do I need to write or die in a sql query?

Question

PHP

In PHP, I write sql queries like this:

I saw that others add this thing to the query: or die("Can't connect."). Does it need to be written? Necessarily?
I also write at the end: , $db). And is it necessary?

Answer 1

or die are added when you need to stop the script on an error, and in brackets the actual text that will be displayed. But, as colleagues unsubscribed above, it is better to use PDO

Answer 2

Discover PDO

Answer 3

Boy, in what library did you find that ancient sinister spellbook of black sorcerers?