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Is two NULL Value's are equal??

  • March 24, 2009 at 12:50 am

    #129979

    If two NULL value's are different then why we cant insert two null values in Unique constraint column. Please anyone can explain this??

    Thanks

  • March 24, 2009 at 12:57 am

    #964988

    In Unique Key consraint only one null value is allowed......

  • March 24, 2009 at 1:37 am

    #964995

    I agree that there are some inconsistencies about NULL values, but maybe you will understand it better if you look at it from another side. Two NULL values are not equal, but also they are not different - they are simply unknown. Unique constraint makes sure that any two values in the column are different.

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