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Why does NULL = NULL evaluate to false in SQL server
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Think of the null as "unknown" in that case (or "does not exist"). In either of those cases, you can't say that they are equal, because you don't know the value of either of them. So, null=null evaluates to not true (false or null, depending on you...
How can I create download link in HTML?
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This answer is outdated. We now have the download attribute. (see also this link to MDN)
If by "the download link" you mean a link to a file to download, use
<a href="http://example.com/files/myfile.pdf" target="_blank">Download</a>
t...
How can I be notified when an element is added to the page?
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Warning!
This answer is now outdated. DOM Level 4 introduced MutationObserver, providing an effective replacement for the deprecated mutation events. See this answer for a better solution than the one presented here. Seriously. Don't poll the DOM ev...
Configure apache to listen on port other than 80
...-default.conf
And change the first line as
<VirtualHost *: 8079>
Now restart
sudo service apache2 restart
Apache will now listen on port 8079 and redirect to /var/www/html
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impr...
Moving average or running mean
... each position in the window, are sometimes called the convolution kernel. Now, the arithmetic mean of N values is (x_1 + x_2 + ... + x_N) / N, so the corresponding kernel is (1/N, 1/N, ..., 1/N), and that's exactly what we get by using np.ones((N,))/N.
Edges
The mode argument of np.convolve speci...
Deny access to one specific folder in .htaccess
... used this to disable direct access to my api files inside /api folder but now all webservice call sending 403 forbidden status .. I just want to block access when someone access it from browser.
– ravisoni
Jul 31 '14 at 9:25
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VIM Disable Automatic Newline At End Of File
...rc) (thanks to 罗泽轩 for that last bit of news!):
:set nofixendofline
Now regarding older versions of vim.
Even if the file was already saved with new lines at the end:
vim -b file
and once in vim:
:set noeol
:wq
done.
alternatively you can open files in vim with :e ++bin file
Yet another alte...
'pip' is not recognized as an internal or external command
...tem variable. By default, pip is installed to C:\Python34\Scripts\pip (pip now comes bundled with new versions of python), so the path "C:\Python34\Scripts" needs to be added to your PATH variable.
To check if it is already in your PATH variable, type echo %PATH% at the CMD prompt
To add the path ...
How do I wait for an asynchronously dispatched block to finish?
..._FOREVER);
} else {
while (dispatch_semaphore_wait(sema, DISPATCH_TIME_NOW)) {
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:0]];
}
}
This should behave correctly even if runSomeLongOperationAndDo: decides that the operat...
What are 'closures' in .NET?
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Thanks Jon. BTW, is there something that you don't know in .NET? :) Who do you go to when you have questions?
– Developer
Jan 9 '09 at 16:12
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