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CHECKING specific values

  • February 24, 2016 at 4:19 pm

    #1860924

    The defaults with a US SQL Server are what I used. I'm not going to list out client settings, collations, etc. If your settings are different, then you'll need to adjust for these questions.

  • February 26, 2016 at 8:10 am

    #1861405

    Sean Lange (2/23/2016)

    I am shocked at how many people (9% at time of this post) said there would be 4 rows. :w00t:

    Excellent question Steve.

    I'm not shocked; several people will be as careless as me :blush: and notice the NULL and then not bother to check whether the other values are valid, sust assuming (wrongly) that the behaviour with NULL is the only point to the question because that's the thing that most people get wrong and that many people claim (because they haven't a clue what the point of NULL is and why it is provided in SQL) is a bad part of the SQL specification of a CHeCk constraint.

    edit: I think the 22% who picked 2 as the answer are are far bigger problem that the 9% who picked 4 - I certinly wouldn't allow any of those 22% to do any schema design until I was certain that they have learned to understand and accept what NULLs are about and how check constraints work and realise that if they don't want to allow NULLs for a column they should declare it as NOT NULL (or, if they want to be stupid about it because they think they know better than Ted Codd, include "COL is not NULL" in their check constraint).

    Tom

  • March 9, 2016 at 4:46 pm

    #1864144

    Thanks for the question.

  • March 10, 2016 at 11:48 am

    #1864346

    Thanks for the question.

    Need an answer? No, you need a question
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