SQL WITH Statements (Common Table Expressions - CTE) 

It's not a requirement but you certainly could

Congrats on your learning Larry. Like all tools, CTEs, subqueries and cursors all have their appropriate use cases. While it is true that you could program almost everything using subqueries, other methods (such as CTEs) could be used as well to make your code easier to follow for those coming behind you to maintain it. Like a painting, everyone has their own style and choice of tools 😉

i know Im kinda off topic but does anyone know a good site to watch new movies online?

@Anthony Edison I use FlixZone. Just google for it =)

@Kameron Deacon yea, I've been watching on FlixZone for since april myself =)

@Kameron Deacon thanks, I signed up and it seems to work =) I really appreciate it !

@Anthony Edison happy to help xD

In most database systems, the 'name' of the CTE simply references an internal temporary table that is invisible to you (unless you select from it). So, in effect, the results of the CTE will create a temporary table behind the scenes in order to hold the results of the CTE. It is deleted automatically when you go out of scope of the CTE.

A temporary table will exist during the entire duration of the session whereas a CTE is a "named result set" that exists for the duration of the statement immediately following it. If you would like to persist the results of the CTE, then use the CTE to populate a temporary table for processing later. Hope this clears things up

Could you elaborate on why one should be careful using temp tables?

@@paradix847 scope, memory and performance issues. if a temp table isn’t dropped and the client makes another request to the server, the temp table that was not disposed correctly can throw ambiguous errors

@@christiangrundemann9843 Hey that's good to have in mind. Thanks for the explanation.

Cte isn't tepm table. It works like a temp table. That's what I know. So no disclaimer.