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MySQL, better to insert NULL or empty string?

...are optional while some are mandatory. In my DB I have a table which holds all these values, is it better practice to insert a NULL value or an empty string into the DB columns where the user didn't put any data? ...
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getting date format m-d-Y H:i:s.u from milliseconds

... I generally opt for the second form as it's easier to read and understand. Additionally, DateTime is far more flexible and robust than the date/time functions. Handling microseconds is a case-in-point. – Herber...
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Do AJAX requests retain PHP Session info?

... What you're really getting at is: are cookies sent to with the AJAX request? Assuming the AJAX request is to the same domain (or within the domain constraints of the cookie), the answer is yes. So AJAX requests back to the same server do ...
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Find the extension of a filename in Ruby

... That's really basic stuff: irb(main):002:0> accepted_formats = [".txt", ".pdf"] => [".txt", ".pdf"] irb(main):003:0> File.extname("example.pdf") # get the extension => ".pdf" irb(main):004:0> accepted_formats.include? ...
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Difference of Maven JAXB plugins

...om.sun.tools.xjc.maven2:maven-jaxb-plugin, the development is active. Finally, I'm one of the authors :) and I'd say we keep in touch with JAXB developers and users and react to the latests features/requests. And indeed, the plugin #2 isn't very active (dead?). And because I've always be...
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install / uninstall APKs programmatically (PackageManager vs Intents)

My application installs other applications, and it needs to keep track of what applications it has installed. Of course, this could be achieved by simply keeping a list of installed applications. But this should not be necessary! It should be the responsibility of the PackageManager to maintain the ...
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What is the Ruby (spaceship) operator?

...irst language to use it. Groovy is another language that supports it. Basically instead of returning 1 (true) or 0 (false) depending on whether the arguments are equal or unequal, the spaceship operator will return 1, 0, or −1 depending on the value of the left argument relative to the right argum...
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The best way to remove duplicate values from NSMutableArray in Objective-C?

...etWithArray:array]; You can then get back an array via array = [orderedSet allObjects]; or just use NSOrderedSets instead of NSArray in the first place. – Regexident May 14 '13 at 9:40 ...
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Setting focus on an HTML input box on page load

... Will that actually set the input focus? Which browser did you try it on? – Peter Mortensen Jul 1 '19 at 1:44 ...
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Understanding the basics of Git and GitHub [closed]

...es and collaborate with other people. Is Git saving every repository locally (in the user's machine) and in GitHub? No, it's only local. You can decide to push (publish) some branches on GitHub. Can you use Git without GitHub? If yes, what would be the benefit for using GitHub? Yes, Git ru...