March 25, 2008 by pinaldave
Yesterday I posted a puzzle SQL SERVER – Simple Puzzle Using Union and Union All, today we will see the answer of this. Following image explains the answer of puzzle.
You can read the explanation of why this is answer read my previous article SQL SERVER – Union vs. Union All – Which is better for performance?
Reference : Pinal Dave (http://blog.SQLAuthority.com)
Pinalkumar Dave is Microsoft SQL Server MVP, Solid Quality Mentor and a prominent author of over 1000 SQL Server articles at SQLAuthority. He is a dynamic and proficient Principal Database Architect, Corporate Trainer and Project Manager specializing in SQL Server Programming with over 7 years of hands-on experience. He holds a degree in Masters of Science and has accomplished a number of certifications including MCDBA and MCAD (.NET). He has also been awarded Regional Mentor for PASS Asia.
pinaldave
[...] : SQL SERVER – Simple Puzzle Using Union and Union All – AnswerReference : Pinal Dave [...]
this is because of union, when ur using union in record than it shows distinct records
yep, the perenthesis are rearanging the order of the unions which is causing the
1 union all (1 union 2) to
(1 union all 1) union 2
trixy!