What do aggregate functions do?

How does the GROUP BY clause work?

What is the difference between a GROUP BY and ORDER BY?

What is the HAVING clause used for?

Can the WHERE clause always be considered a substitute for the HAVING clause? Why or why not?

Do functions of functions have to be handled in a special way in Server SQL 2005?

Will nulls in grouped columns be included in a result set?

How do aggregate functions treat nulls?

Does the sequence of the columns in a GROUP BY clause have an effect on the end result?

When would it not make sense to use the GROUP BY and DISTINCT functions together?

Is GROUP BY affected by nulls?

Which comes first in a SELECT statement, an ORDER BY or GROUP BY? Why?

The GROUP BY and ________________ clauses are used together.