Sams Teach Yourself Transact-SQL in 21 Days, Second Edition

Day 6

Quiz

1:	How many tables can appear in a single query?
A1:	In previous releases of SQL Server, there was a limit of 16 tables. However, Microsoft has increased this limit to 256, which is probably more than any query you write will ever need.
2:	Can a subquery be run as a join or vice versa?
A2:	Yes, in most cases, a subquery can be implemented as a join or vice versa.
3:	In which SQL clauses may a subquery appear?
A3:	A subquery can be used in any SELECT, WHERE, and HAVING statement or clause.

Exercises

These exercises use the Pubs database.

1:	List the authors who have at least one book priced above the average price.
A1:	This one is a bit harder than it looks. To answer it, you must use the Authors table to get the author names, the Sales table ...