Gurus Place

NULL Is Not A Value

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  |
+----------+

alright Now:
SELECT count(*) from some_table WHERE (condition_a) AND (condition_b);

+----------+
| count(*) |
+----------+
|     0    |
+----------+
aha Ok then:
SELECT count(*) from some_table WHERE condition_a AND NOT (condition_b);
The result was also
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  |
+----------+

alright Now:
SELECT count(*) from some_table WHERE (condition_a) AND (condition_b);

+----------+
| count(*) |
+----------+
|     0    |
+----------+

HA !!!!
Ok for those 11223 records the condition_a was true, from the second statement I could tell that condition_b was false, so NOT condition_b should be true, but it was also false from the third statement.
So for Logic to play around condition_b, and NOT condition_b both are false (How can that be) all theories of logic are broken (what is going on?)
After breaking up the two conditions, I found that I was comparing one of the values in condition_b with NULL, so in BOTH cases the result would be FALSE (or actually UNKNOWN which is casted to NULL), I’ve always assumed that NULL would be casted to 0, but the fact that it’s not.
So this was just a thing that you might want to take care of when you write your SQL statements.
Hope it was Useful

Chain Letters

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.

more

So, let’s define “chain letter”. A chain letter is ANY e-mail that contains instructions to “forward this out” or “forward this to everyone you know” or anything else of that nature. Who creates chain letters? Now you might want to think that when you get an e-mail telling you there’s some sick child with cancer and they will receive $0.03 for every time this e-mail gets forwarded out, in fact the mental image may just tug at your heart strings so bad that you forward it to other news or joke lists that you’re on, in hopes of spreading the word and bring hope to this poor kid.

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Well, guys, the thing I hate more than receiving SPAM, is receiving Chain Letters, it usually has a big size, as everybody in the whole stupid part of the earth, has forwarded it to somebody else who has forwarded it to another body to ….. and forwarded it to me.
Alright, there is no sick girl whom AOL has paid a fu***** cent for each one receiving a damn message, Hotmail is not going to delete your account if you don’t send this message, (they can know when was the last time you logged in to make sure you are using it), and Bill Gates is not throwing money over anybody, and you wont get a free mobile, or a free shit or anything. you are not going to be rich or anything.
Chain Messages are used by spammers, as they collect as much emails as they want throw this thing, imagine a single chain message going around, and then getting back to the same spammer who sent it, how many emails he would’ve received. What could happen if people were wise enough not send this shit all around? do you enjoy having this FREE SOFTWARE, or VIAGRA, or stupid things going around in you’re mailbox? if no, then stop forwarding this damn emails.
if you are not convinced yet, well then enjoy your life, but don’t send me any stupid chain message.

Apple Launches New Site for Open Source

Mac OS Forge dedicated to projects focused on Mac OS X.

Mac OS Forge, a new community development site hosted by Apple, was recently launched to support Web Kit and other open source projects focused on Mac OS X. In addition, developers can create and browse third-party open source projects that are closely related to the Macintosh operating system. Current projects on Mac OS Forge include source code to the new iCal Server in Leopard Server, and Apache-licensed versions of Bonjour service discovery and Launchd process management.

While select projects in Mac OS X are featured on Mac OS Forge, a complete set of open source software within Mac OS X can be found by visiting the Apple Developer Connection.

Taken form the Apple Developer Connection newsletter

Zend Certificate: PHP5 Exam Festival

A PHP5 Exam Festival is being prepared in Amman by the end of July - first of August. Event will be sponsored by Zend.

First Of June (Something New)

Well, it was a rough day, also a lot of new things were done.
First thing Maktoob.com launched their new Home Page, it’s really nice, also the NoLimits thing where now you can take an unlimited storage for your email at maktoob, also by the end of the day also Maktoob-Women section (Beta Version) was launched too, it’s really nice.
In the middle of the day I found that Ubuntu at last realesed their dapper version (I’ve been using it for about 2 months through all the alpha beta thing, also my CD’s are on there way :P), well they’ve done a lot of good stuff in it.
In the end of the day I received an email from Zend.com informing me that Zend Studio Version 5.2 has been released too, I really love this software, it really makes my life easier.
Well I guess there is something new about this June …

Free Software Magazine Issue 11 is out

The latest issue of FSM is out and can be read online or downloaded for free. That’s 11 new articles to read.

read more | digg story

Kubuntu.de Protestwoche

To calrify the seriosness of the situation, kubuntu.de will be offline for one week beginning as from Monday, 10.04.2006 …

Kubuntu.de Started a Protest Week

This website, including the forum, the mailing lists and the respective IRC channels (#kubuntu-de and #kubuntu-de-team) has one aim: to support the community, to offer a platform to the users of Kubuntu and, last but not least, to boost the Kubuntu-project so as to make it an outstanding distribution.

More …

I just recieved this note from LinuxToday, well it so sad to see an opensource project reaches this point, but I’m speachless here.

Technorati Tags: Protest, Kubuntu.de, opensource,

Firefox 2.0 alpha available

If you aspire to be an early adopter, here’s your chance. An alpha version of Firefox 2.0 called “Bon Echo” is available on Mozilla’s FTP servers, and you can choose from the Windows version, Mac OS X version, or Linux version.

Due out later this year, Firefox 2.0 promises a handful of improvements and new features over what is already a very solid browser. (By way of disclosure, I use Firefox 1.5 exclusively on my PC.)

Version 2.0 has a handful of new features. One of the more interesting features is the revamped places menu, which is accessible from the bookmarks toolbar. Clicking on that brings up a box that will allow you to search your history, bookmarks, and RSS subscriptions for a keyword. Very useful if you remember reading about something interesting earlier in the day and need to quickly locate the web page again. Aesthetically speaking, there are a few minor tweaks to the UI, such as Xs on inactive tabs for easy closing.

Google’s antiphishing tech is also planned for inclusion in a future version of Firefox. Although it does not appear to be incorporated into this early alpha of 2.0, Google Safe Browsing—which uses a combination of blacklisting and “best guesses” about a site’s intention—may yet make it into the final release of Firefox 2.0.

Technorati Tags: Firefox, Release

Taking a look at PHP 6

While most web hosts are still in the PHP 4 era, the PHP developers are already planning and working on PHP 6. Lets have a look at what’s been keeping them busy.
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Technorati Tags: PHP, Release

old File

This program is a semulation of a process management system.
I wrote in 3rd year, after I took the OS course, so hope it might be useful for some people.
jobmanagement.c
Enjoy …
I published it before, I thought it won’t harm if I do it again.

Technorati Tags: c, programming, OS