Question 6

Answer C is correct. You are probably not ordering the data to achieve the desired results. Grouping of the result set doesn't seem to be warranted because the question is asking for five rows. NULL values should not affect this query, although in some instances, NULL data can interfere with the results.

For more information, see the following sources:

• Chapter 3, "Implementing Database Objects"

• SQL Server 2005 Books Online: "SQL Server Database Engine, Accessing and Changing Database Data, Query Fundamentals, Grouping Rows, Sorting Rows with Order By"

• "Accessing and Changing Relational Data Overview," http://msdn.microsoft.com/library/default.asp?url=/library/en-us/acdata/ac_oview_4pcx.asp

• Within MSDN Library, go to MSDN Home, MSDN Library, Servers and Enterprise Development, SQL Server, Writing SQL Queries: Let's Start with the Basics.