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Can I have multiple primary keys in a single table?
...re UNIQUE, taken together, and also NOT NULL. Thus, specifying values for all the columns of any candidate key is enough to determine that there is one row that meets the criteria, or no rows at all.
Candidate keys are a fundamental concept in the relational data model.
It's common practice, if m...
Is the pImpl idiom really used in practice?
...y Herb Sutter, and in that book I have learned about the pImpl idiom. Basically, the idea is to create a structure for the private objects of a class and dynamically allocate them to decrease the compilation time (and also hide the private implementations in a better manner).
...
Powershell v3 Invoke-WebRequest HTTPS error
...19466/new-webserviceproxy-needs-force-parameter-to-ignore-ssl-errors
Basically, in your PowerShell script:
add-type @"
using System.Net;
using System.Security.Cryptography.X509Certificates;
public class TrustAllCertsPolicy : ICertificatePolicy {
public bool CheckValidationResul...
Visual Studio Project vs. Solution
...etermines its 'granularity') is that one project produces one output: typically an executable or a library (dll). So, if you are going to code three executables that uses related code, you'll create one solution and at least three projects - probably more.
...
Renaming projects in Xcode 4
...
Well, it turned out to be a trivial matter indeed.
All you need to do is click twice slowly on the project root in the project navigator and it then becomes editable. After you rename the project and press 'enter' it will suggest to automatically change all project-name-relat...
Case insensitive string as HashMap key
...eMap =
new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
That's really all you need.
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How to see an HTML page on Github as a normal rendered HTML page to see preview in browser, without
...b Pages to render this.
Fork the repository to your account.
Clone it locally on your machine
Create a gh-pages branch (if one already exists, remove it and create a new one based off master).
Push the branch back to GitHub.
View the pages at http://username.github.io/repo`
In code:
git clone g...
What is the difference between an abstract function and a virtual function?
...
An abstract function cannot have functionality. You're basically saying, any child class MUST give their own version of this method, however it's too general to even try to implement in the parent class.
A virtual function, is basically saying look, here's the functionality that may...
How to make zsh run as a login shell on Mac OS X (in iTerm)?
.... This can happen if you're changing, for example, to a version of zsh installed by homebrew, which puts it in /usr/local/bin/zsh.
– shovavnik
Oct 30 '14 at 20:32
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Xml configuration versus Annotation based configuration [closed]
...nformation. But if you like JPA (I don't have any expirience with it), by all means, go for it.
In general:
If an annotation provides functionality and acts as a comment in and of itself, and doesn't tie the code down to some specific process in order to function normally without this annotation, ...