This is one of the classic schoolbook databases to learn database design. Maybe you should read one?

Sounds like you either didn't do any relational theory in class or you didn't ever read the homework assignments. This is database design 101.

What is "true" or not depends on your business rules.

The easiest way to do this is one relation at a time in your ERD. If you don't know how...

Lookups are going to bite you. Remove them all, then move to SQL Server. They don't exist in SQL Server, and didn't exist in Access for a long time. Here's...

This is a homework assignment. I know, I did it when I studied too. Do your own homework. =)

You could pivot this stuff in a Matrix in SSRS and be done already. Is that not an option? Wouldn't be if you had to output this result for...

How many possible combinations are there for "formula"? You could write a CASE statement that determined which formula to use to calculate the answer... surely must be faster than a...

Took me a minute... if you use Windowing functions (requires SQL 2012 or later), then this is easy. The PARTITION basically groups the records together... then you can use...

Maybe a ForEach table loop and a LEFT OUTER JOIN?

If you split the Date and Time fields into two different columns in SQL Server, then this query is trivial.

Don't understand why you think you need windowing functions...

Does this do what you want? The inner query, inside the parentheses... query "x", gets the counts for each grouping, and then...

you can use plain old DATEADD if you're just counting days, without respect to holidays and weekends... but until you post actual consumable data, it's hard to tell.

Okay, this is getting pretty old. If you don't want to post some sample consumable data... a CREATE TABLE script and some INSERTs to populate the table(s), then I guess...

So you create a Calendar table to have as many days as you need, and when the new year rolls around, you add more dates. Sure, you have to...

It should work. The main reason for using the Calendar is that you're guaranteed no gaps in the dates. It also gives you a handy table to group on....