Tutorial by Examples: d

A true relational database must go beyond throwing data into a few tables and writing some SQL statements to pull that data out. At best a badly designed table structure will slow the execution of queries and could make it impossible for the database to function as intended. A database table shoul...

Apply will be used when when table valued function in the right expression. create a Department table to hold information about departments. Then create an Employee table which hold information about the employees. Please note, each employee belongs to a department, hence the Employee table has ref...

In normal mode, we can increment the nearest number on the line at or after the cursor with <C-a> and decrement it with <C-x>. In the following examples, the cursor position is indicated by ^. Incrementing and decrementing numbers for i in range(11): ^ <C-x> decrements ...

The Math.random() function should give random numbers that have a standard deviation approaching 0. When picking from a deck of card, or simulating a dice roll this is what we want. But in most situations this is unrealistic. In the real world the randomness tends to gather around an common normal...

Common Lisp REPL is an interactive environment. Every form written after the prompt is evaluated, and its value is afterwards printed as result of the evaluation. So the simplest possible “Hello, World!” program in Common Lisp is: CL-USER> "Hello, World!" "Hello, World!" CL...

Flash Player 10 introduced the Vector.<*> generic list type that was faster than the Array. However, this is not entirely true. Only the following Vector types are faster than the Array counterparts, due to the way they are implemented in Flash Player. Vector.<int> - Vector of 32-bit ...

Creating and configuring Sprite and TextField objects at runtime can be costly if you are creating hundreds of thousands of these on a single frame. Therefore a common trick is "pooling" these objects for later reuse. Remember we are not just trying to optimize the creation time (new Sprit...

Flash dispatches Events for most of its objects. One of the most basic event is ENTER_FRAME, which is dispatched (at the framerate of the SWF) on every display list object. import flash.display.Sprite; import flash.events.Event; var s:Sprite = new Sprite(); s.addEventListener(Event.ENTER_FRAME...

You can create your own events and dispatch them, by extending the Event class. import flash.events.Event; class MyEvent extends Event { var data: String; static public var MY_EVENT_TYPE = "my_event_my_event_code"; public function MyEvent(type: String, data: Str...

Codename One is a set of tools for mobile application development that derive a great deal of its architecture from Java. Codename One's mission statement is: Unify the complex and fragmented task of mobile device programming into a single set of tools, APIs & services. As a result create a...

UITextView has built in support to auto detect a variety of data. The data that is able to be auto-detected currently includes: enum { UIDataDetectorTypePhoneNumber = 1 << 0, UIDataDetectorTypeLink = 1 << 1, UIDataDetectorTypeAddress = 1 << 2, UID...

Single JAR Sometimes you have a local JAR file you need to add as a dependency to your Gradle build. Here's how you can do this: dependencies { compile files('path/local_dependency.jar') } Where path is a directory path on your filesystem and local_dependency.jar is the name of your local...

Dependencies in Gradle follow the same format as Maven. Dependencies are structured as follows: group:name:version Here's an example: 'org.springframework:spring-core:4.3.1.RELEASE' To add as a compile-time dependency, simply add this line in your dependency block in the Gradle build file: ...

It is possible to find the first element of a Stream that matches a condition. For this example, we will find the first Integer whose square is over 50000. IntStream.iterate(1, i -> i + 1) // Generate an infinite stream 1,2,3,4... .filter(i -> (i*i) > 50000) // Filter to find element...

Template JS code Template.templateName.onCreated(function(){ this.subscribe('subsription1'); this.subscribe('subscription2'); }); Template HTML code <template name="templateName"> {{#if Template.subscriptionsReady }} //your actual view with data. it can ...

Variables can be incremented or decremented by 1 with ++ or --, respectively. They can either precede or succeed variables and slightly vary semantically, as shown below. $i = 1; echo $i; // Prints 1 // Pre-increment operator increments $i by one, then returns $i echo ++$i; // Prints 2 // P...

Defining our terms By array here we mean a Lua table used as a sequence. For example: -- Create a table to store the types of pets we like. local pets = {"dogs", "cats", "birds"} We're using this table as a sequence: a group of items keyed by integers. Many langua...

Files: - example.rs (root of our modules tree, generally named lib.rs or main.rs when using Cargo) - first.rs - second/ - mod.rs - sub.rs Modules: - example -> example - first -> example::first - second -> example::second - sub -> exampl...

It's fairly common that you may create a class that implements IDisposable, and then derive classes that also contain managed resources. It is recommendeded to mark the Dispose method with the virtual keyword so that clients have the ability to cleanup any resources they may own. public class Paren...

This example wraps the asynchronous method oauth2.client.getToken(callback) from the package NPM package simple-oauth2into a Fiber so that the method may be called synchronously. const oauth2 = require('simple-oauth2')(credentials); const credentials = { clientID: '#####', clientSecret...