Char with null

  • tejinder.barnala

    Old Hand

    Points: 354

    Comments posted to this topic are about the item Char with null

  • Russell Shilling

    SSCarpal Tunnel

    Points: 4274

    The answer is clearly wrong. Some of these questions are really questionable.

    The

    isnull(left(@b,3),'I ô Char') as ba

    will also return the string. The left function of @B returns NULL.

    So long, and thanks for all the fish,

    Russell Shilling, MCDBA, MCSA 2K3, MCSE 2K3

  • Rune Bivrin

    SSCertifiable

    Points: 7618

    Russell Shilling (1/10/2017)


    The answer is clearly wrong. Some of these questions are really questionable.

    The

    isnull(left(@b,3),'I ô Char') as ba

    will also return the string. The left function of @B returns NULL.

    Well, if you'd run the code you'd find it's completely correct.

    What's missing in the explanation is the behaviour of ISNULL(). It always derives its return type from the first argument, which in the "ba" case will be char(3) as that is what LEFT() will return.


    Just because you're right doesn't mean everybody else is wrong.

  • sendijunk

    Mr or Mrs. 500

    Points: 544

    Good question. Could use a bit more explanation though. Interesting what happens if you replace ISNULL with COALESCE.

  • Carlo Romagnano

    SSC-Insane

    Points: 21833

    sendijunk (1/11/2017)


    Good question. Could use a bit more explanation though. Interesting what happens if you replace ISNULL with COALESCE.

    The return type depends on "precedence" of types. In this case, the longest string of 8 chars.

  • Ed Wagner

    SSC Guru

    Points: 286960

    And here I was looking for the trick. 😉 Thanks.

  • Bob Razumich

    SSCrazy

    Points: 2011

    Rune Bivrin (1/10/2017)


    Russell Shilling (1/10/2017)


    The answer is clearly wrong. Some of these questions are really questionable.

    The

    isnull(left(@b,3),'I ô Char') as ba

    will also return the string. The left function of @B returns NULL.

    Well, if you'd run the code you'd find it's completely correct.

    What's missing in the explanation is the behaviour of ISNULL(). It always derives its return type from the first argument, which in the "ba" case will be char(3) as that is what LEFT() will return.

    And for those inquiring minds that would like a quick link for the ISNULL function, https://msdn.microsoft.com/en-us/library/ms184325.aspx.

  • akljfhnlaflkj

    SSC Guru

    Points: 76202

    I've been caught by these before so had to try it out.

  • Sean Lange

    SSC Guru

    Points: 286486

    Rune Bivrin (1/10/2017)


    Russell Shilling (1/10/2017)


    The answer is clearly wrong. Some of these questions are really questionable.

    The

    isnull(left(@b,3),'I ô Char') as ba

    will also return the string. The left function of @B returns NULL.

    Well, if you'd run the code you'd find it's completely correct.

    What's missing in the explanation is the behaviour of ISNULL(). It always derives its return type from the first argument, which in the "ba" case will be char(3) as that is what LEFT() will return.

    +1

    The question itself I thought was a great question but the explanation skipped the important part about the return datatype from ISNULL.

    I look forward to the next question from Tejinder and hope the explanation is as good as the question next time.

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  • Revenant

    SSC-Forever

    Points: 42467

    Iwas Bornready (1/11/2017)


    I've been caught by these before so had to try it out.

    Me, too.

    Thanks, Tejinder!

  • This was removed by the editor as SPAM

  • TomThomson

    SSC Guru

    Points: 104772

    Russell Shilling (1/10/2017)


    The answer is clearly wrong. Some of these questions are really questionable. The

    isnull(left(@b,3),'I ô Char') as ba

    will also return the string. The left function of @B returns NULL.

    Well, if you'd run the code you'd find it's completely correct. What's missing in the explanation is the behaviour of ISNULL(). It always derives its return type from the first argument, which in the "ba" case will be char(3) as that is what LEFT() will return.

    I guess we now have additional evidence of the value (or lack thereof) of MCDBA, MCSA, and MCSE qualifications in filtering CVs.

    Tom

  • tejinder.barnala

    Old Hand

    Points: 354

    Revenant - Wednesday, January 11, 2017 9:17 AM

    Iwas Bornready (1/11/2017)


    I've been caught by these before so had to try it out.

    Me, too.Thanks, Tejinder!

    thanks everyone for their comments / feedback. i agree explanation of the answer was not upto mark . i will try to be more clear in future

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