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Sep 10 2006

NULL Is Not A Value

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Before a few months, I was working on some mysterious issue regarding some SQL statements, it was something like this.
SELECT count(*) from some_table WHERE (condition_a);
the result was:

+----------+
| count(*) |
+----------+
|   11223  |
+----------+

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Sep 10 2006

Chain Letters

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A typical chain letter consists of a message that attempts to induce the recipient to make a number of copies of the letter and then pass them on to one or more new recipients. A chain letter can be considered a type of meme, a self-replicating piece of information that uses a human host to distribute copies of itself. Common methods used by chain letters include emotionally manipulative stories, get-rich-quick pyramid schemes, and the exploitation of superstition to threaten the recipient with bad luck or even physical violence if he or she “breaks the chain” and refuses to adhere by the conditions set out by the letter.

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