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JOIN queries vs multiple queries
...ral queries? (You run your main query, and then you run many other SELECTs based on the results from your main query)
14 An...
Conditionally ignoring tests in JUnit 4
... like this:
@Test
public void calculateTotalSalary() {
assumeThat(Database.connect(), is(notNull()));
//test code below.
}
Not to mention that it is much easier to capture and use the connection from the Database.connect() method this way.
...
Java - JPA - @Version annotation
...oesn't matter if application uses only JPA for inserting data into the database, as JPA vendor will enforce 0 for @version field at creation time. But almost always plain SQL statements are also in use (at least during unit and integration testing).
...
Heroku/devise - Missing host to link to! Please provide :host parameter or set default_url_options[:
...nes to config/environments/production.rb in your app.
.
ActionMailer::Base.smtp_settings = {
:address => 'smtp.sendgrid.net',
:port => '587',
:authentication => :plain,
:user_name => ENV['SENDGRID_USERNAME'],
:password => ENV['SENDG...
What is the difference between a HashMap and a TreeMap? [duplicate]
...
To sum up:
HashMap: Lookup-array structure, based on hashCode(), equals() implementations, O(1) runtime complexity for inserting and searching, unsorted
TreeMap: Tree structure, based on compareTo() implementation, O(log(N)) runtime complexity for inserting and searchi...
How to call asynchronous method from synchronous method in C#?
...
Asynchronous programming does "grow" through the code base. It has been compared to a zombie virus. The best solution is to allow it to grow, but sometimes that's not possible.
I have written a few types in my Nito.AsyncEx library for dealing with a partially-asynchronous code b...
Difference between Convert.ToString() and .ToString()
...tring tries to use IFormattable and IConvertible interfaces before calling base Object.ToString.
Example:
class FormattableType : IFormattable
{
private double value = 0.42;
public string ToString(string format, IFormatProvider formatProvider)
{
if (formatProvider == null)
...
How is OAuth 2 different from OAuth 1?
...key differences:
More OAuth Flows to allow better support for non-browser based applications. This is a main criticism against OAuth from client applications that were not browser based. For example, in OAuth 1.0, desktop applications or mobile phone applications had to direct the user to open th...
What is the best CSS Framework and are they worth the effort?
...ly missing the point.
CSS is not like JavaScript, where you can include a base library/framework and then call functions and objects from it to do higher-level work. All a CSS framework can give you is declarative rules: some default browser-rule-reset stuff, some class styles to be forced to autho...
Global and local variables in R
...erstanding how to use them:
http://stat.ethz.ch/R-manual/R-devel/library/base/html/environment.html
http://stat.ethz.ch/R-manual/R-devel/library/base/html/get.html
Here you have a small example:
test.env <- new.env()
assign('var', 100, envir=test.env)
# or simply
test.env$var <- 100
get...