• I'm not ashamed to admit that I've read this problem and the solution several times, as well as the corresponding BOL topics, and I still can't make heads or tails of it. This question has easily made me feel more thick-headed than any other I've seen here, so well done, Honza! Ultimately I had to pick an answer at random just so I could get to the forum thread, where hopefully my head will be pulled from my a** with a resounding POP! 😀

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    a haiku...

    NULL is not zero
    NULL is not an empty string
    NULL is the unknown