Does NULL <> 'string'?

Richard Deeming

Chris Maunder wrote:

We're trying to find the number of records in TableOne which, when joined with TableTwo, either have no corresponding TableTwo row or the corresponding TableTwo row is not 'value'.

Either I've misunderstood your requirement, or that query isn't technically correct. The query will find the records in TableOne which don't have any corresponding rows in TableTwo, and the records in TableOne which have at least one corresponding record in TableTwo where StringColumn is Null or not equal to 'value'. If there are multiple matching rows in TableTwo, then the rows from TableOne will be repeated. Based on the description, I'd have thought something like this would be a better fit:

SELECT Count(1)
FROM TableOne
WHERE Not Exists
(
SELECT 1
FROM TableTwo
WHERE TableTwo.TableTwoID = TableOne.TableTwoID
And TableTwo.StringColumn = 'value'
)

That finds all the rows in TableOne which don't have a corresponding row in TableTwo with StringColumn set to 'value'.

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

Richard Deeming

True, False, and FileNotFound. :-D What Is Truth? - The Daily WTF[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

Jeremy Falcon

I feel ya man. NULL has always been a special case though. It's the bastard stepchild of values. Isn't technology fun?

Jeremy Falcon

Jeremy Falcon

I think this version reads cleaner (and without the quirks), but I'd be willing to bet the non-sub select version would run quicker.

Jeremy Falcon

TheGreatAndPowerfulOz

Jeremy Falcon wrote:

would run quicker

Indeed.

#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun

TheGreatAndPowerfulOz

This proves SQL is not a real programming language.

#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun

Chris Maunder

Au contraire. It's the perfect language. Job security forever.

cheers Chris Maunder

TheGreatAndPowerfulOz

LOL. Especially when you have your own company! ;P

#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun

Erick Mattew

Quote:

Job security forever

Indeed. Writing script, backup,... It's boring but secure.

Jeremy Falcon

So is prostitution... but ya know... :~

Jeremy Falcon

Jorgen Andersson

Assuming SQL Server, I'll take that bet. NOT IN vs. NOT EXISTS vs. LEFT JOIN / IS NULL: SQL Server at EXPLAIN EXTENDED[^] Left outer join vs NOT EXISTS | SQL in the Wild[^] There are always exceptions, but not exists is generally better optimized.

Wrong is evil and must be defeated. - Jeff Ello

OriginalGriff

It gets Dali-esque as well from time to time...

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay... AntiTwitter: @DalekDave is now a follower!

Jorgen Andersson

Boring?

Wrong is evil and must be defeated. - Jeff Ello

Jeremy Falcon

Some are... so I'm told. :rolleyes:

Jeremy Falcon

TheGreatAndPowerfulOz

They don't all "enjoy" it. It's a job. Indeed, prostitutes go same-sex for their personal one-on-ones because opposite-sex has lost all appeal due to the "job".

#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun

Jagger B

Sorry, You failed the interview. He'll call you next time. :|

Jeremy Falcon

So wait, you're saying I can't be a prostitute? Why? Because I'm a guy? That's discrimination.

Jeremy Falcon

Jagger B

Are you saying, Sql Dev's = prostitute?

Jeremy Falcon

Yes. Everyone knows you have go through prostitute training to get certified. You just finding this out? You may wanna talk to your MS rep.

Jeremy Falcon

Nelek

OriginalGriff wrote:

Dali-esque

Surrealistic? or womenizer? :laugh: :laugh: :laugh: :laugh:

M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.