SQL SERVER – SQL Puzzle of SET ANSI_NULL – Win USD 50 worth Amazon Gift Cards and Bubble Copter R/C

Note: This contest is over, so enjoy the brain teaser about ANSI_NULL. We all love puzzles and here is interesting puzzle which you can play with me and win Amazon Gift Cards and Bubble Copter R/C. The contest for Amazon Gift Card is open worldwide, however, Bubble Copter winner will be chosen from USA only.

First run following script:

SET ANSI_NULLS ON;
-- Query1
SELECT 'SQLAuthority' AS Statement11
WHERE 'Authority' IN ('S','Q', 'L', 'Authority', NULL);
-- Query 2
SELECT 'SQLAuthority' AS Statement12
WHERE 'Authority' NOT IN ('S','Q', 'L', NULL);

You will get the following result:

You can clearly see that in the first case we are getting different results. Here are the questions you need to answer to win the Amazon Gift Cards and Bubble Copter R/C.

There are two steps to take participate in the contest:

Step 1: Answer the Question

Question: Why do Query 1 return results but Query 2 does not return any result?

Answer this question in comments area along with the question in Step2.

Giveaway:

• 2 lucky winners will get USD 25 worth Amazon Gift Card (Open worldwide, Total giveaway value USD 50)
• One lucky winner from USA will get  Bubble Copter R/C (Shipping from USA to other countries is not possible)

Rules and Conditions:

• Contest open till May 25, 2013 12:00 GMT. 
• Please leave your answer in the comment area in following format:
  • Answer to Q1:
• Please note that winner will be selected after May 25th by random selection and will be posted as a comment to this blog.
• The answers will be kept hidden till the winner will be announced to have fair competition.

Reference: Pinal Dave (https://blog.sqlauthority.com)