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What are database normal forms and can you give examples? [closed]
...imply normalization, which is a process of organizing columns (attributes) and tables (relations) to reduce data redundancy and improve data integrity. (as written on Wikipedia ).
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Strange, unexpected behavior (disappearing/changing values) when using Hash default value, e.g. Hash
...ior applies to any default value that is subsequently mutated (e.g. hashes and strings), not just arrays.
TL;DR: Use Hash.new { |h, k| h[k] = [] } if you want the most idiomatic solution and don’t care why.
What doesn’t work
Why Hash.new([]) doesn’t work
Let’s look more in-depth at why...
Chrome: timeouts/interval suspended in background tabs?
...appliances not dramatically inaccurate. Now if I run the test in in Chrome and let it run in a background tab (so, switching to another tab and browse on there), returning to the test and inspecting te results (if the test finished) they are dramatically changed. It looks like the timeouts have been...
Easiest way to compare arrays in C#
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Also for arrays (and tuples) you can use new interfaces from .NET 4.0: IStructuralComparable and IStructuralEquatable. Using them you can not only check equality of arrays but also compare them.
static class StructuralExtensions
{
public...
Is recursion ever faster than looping?
I know that recursion is sometimes a lot cleaner than looping, and I'm not asking anything about when I should use recursion over iteration, I know there are lots of questions about that already.
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Gem::LoadError for mysql2 gem, but it's already in Gemfile
...his question by me 8 September 2015 so use the above line in your Gem file and run:
bundle install
You should be good to go
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vagrant up failed, /dev/vboxnetctl: no such file or directory
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I'm running macOS High Sierra 10.13.1 and VirtualBox 5.2.2.
This worked for me:
Grant permission to VirtualBox under System Preferences > Security & Privacy > General (this request is new to macOS High Sierra)
Open Terminal and run: sudo "/Library/Appl...
Most efficient way to increment a Map value in Java
...ood answers to this question--thanks folks--so I decided to run some tests and figure out which method is actually fastest. The five methods I tested are these:
the "ContainsKey" method that I presented in the question
the "TestForNull" method suggested by Aleksandar Dimitrov
the "AtomicLong" meth...
CSS table column autowidth
... width: 1px;
white-space: nowrap;
}
Flexible, Class-Based Solution
And a more flexible solution is creating a .fitwidth class and applying that to any columns you want to ensure their contents are fit on one line:
td.fitwidth {
width: 1px;
white-space: nowrap;
}
And then in your ...
How can I add additional PHP versions to MAMP
The current version of MAMP that I have only has php 5.2.17 and 5.4.4. I need 5.3.X. Is there a way to add additional versions that can be selected in the MAMP interfaces php preferences? This is for the free version of MAMP, not MAMP PRO.
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