Tutorial by Examples: g

For example: You are going to migrate an existing column from non-required to required. In this case you might need to fill some default values in your migration for rows where the altered fields are actually NULL. In case the default value is simple (e.g. "0") you might use a default or d...

Pigeonhole Sort is a sorting algorithm that is suitable for sorting lists of elements where the number of elements (n) and the number of possible key values (N) are approximately the same. It requires O(n + Range) time where n is number of elements in input array and ‘Range’ is number of possible va...

If you're creating an image, decoding an image, or resizing an image to fit the large notification image area, you can get the correct pixel dimensions like so: Resources resources = context.getResources(); int width = resources.getDimensionPixelSize(android.R.dimen.notification_large_icon_width)...

ghci> :set -XOverloadedStrings ghci> import Data.Text as T isInfixOf :: Text -> Text -> Bool checks whether a Text is contained anywhere within another Text. ghci> "rum" `T.isInfixOf` "crumble" True isPrefixOf :: Text -> Text -> Bool checks whether a...

To render your new component in a view, you cust call: @Html.Action("MemberLoginForm", "MemberLoginSurface")

{-# LANGUAGE OverloadedStrings #-} import qualified Data.Text as T myText :: T.Text myText = "mississippi" Characters at specific indices can be returned by the index function. ghci> T.index myText 2 's' The findIndex function takes a function of type (Char -> Bool) ...

Processing provides method ellipse in order to draw ellipse. This code draws a white circle which has radius of 25 pixels. void setup() { size(500, 500); background(0); fill(255); noStroke(); } void draw() { ellipse(225, 225, 50, 50); } The signature of method ellip...

Git config allows you to customize how git works. It is commonly used to set your name and email or favorite editor or how merges should be done. To see the current configuration. $ git config --list ... core.editor=vim credential.helper=osxkeychain ... To edit the config: $ git config &lt...

Method overloading is the way of using polymorphism inside a class. We can have two or more methods inside the same class, with different input parameters. Difference of input parameters can be either: Number of parameters Type of parameters (Data type) Order of the parameters Let's take a ...

For Umbraco 7 the requirements are IIS 7 or higher Database, one of the following: SQL CE, SQL Server 2008 or higher or MySQL with support for case insensitive queries) ASP.NET 4.5 or 4.5.1. Full-Trust Ability to set file/folder permissions for the user that "owns" the Application P...

Check for updates to the Nuget package manager. In Visual Studio: Tools > Extensions and Updates > Updates > Visual Studio Gallery. Install if availalbe Create a new web application with template "ASP.NET Web Application with an Empty template" on .NET Framework 4.5.1 Open the...

The Memory Model is difficult to understand, and difficult to apply. It is useful if you need to reason about the correctness of multi-threaded code, but you do not want to have to do this reasoning for every multi-threaded application that you write. If you adopt the following principals when wri...

Let's make a function to divide two numbers, that's very trusting about its input: def divide(x, y) return x/y end This will work fine for a lot of inputs: > puts divide(10, 2) 5 But not all > puts divide(10, 0) ZeroDivisionError: divided by 0 > puts divide(10, 'a') TypeE...

You can save the error if you want to use it in the rescue clause def divide(x, y) begin x/y rescue => e puts "There was a %s (%s)" % [e.class, e.message] puts e.backtrace end end > divide(10, 0) There was a ZeroDivisionError (divided by 0) from ...

If you want to do different things based on the kind of error, use multiple rescue clauses, each with a different error type as an argument. def divide(x, y) begin return x/y rescue ZeroDivisionError puts "Don't divide by zero!" return nil rescue TypeError put...

In a rescue clause, you can use retry to run the begin clause again, presumably after changing the circumstance that caused the error. def divide(x, y) begin puts "About to divide..." return x/y rescue ZeroDivisionError puts "Don't divide by zero!" y = ...

You can use an else clause for code that will be run if no error is raised. def divide(x, y) begin z = x/y rescue ZeroDivisionError puts "Don't divide by zero!" rescue TypeError puts "Division only works on numbers!" return nil rescue => e ...

select sysdate from dual

select :start_value + level -1 n from dual connect by level <= :end_value - :start_value + 1

Qt offers a deployment tool for Mac: The Mac Deployment Tool. The Mac deployment tool can be found in QTDIR/bin/macdeployqt. It is designed to automate the process of creating a deployable application bundle that contains the Qt libraries as private frameworks. The mac deployment tool also deploys...