Tutorial by Examples: r

This simple function will execute the specified Select SQL command and return the result as data set. Public Function ReadFromDatabase(ByVal DBConnectionString As String, ByVal SQL As String) As DataTable Dim dtReturn As New DataTable Try 'Open the connection using the connection...

This example uses the Thread Class, but multithreaded applications can also be made using BackgroundWorker. The AddNumber, SubstractNumber, and DivideNumber functions will be executed by separate threads: Edit: Now the UI thread waits for the child threads to finish and shows the result. Module Mo...

Unlike a SELECT statement, a Stored Procedure returns multiple result sets. The requires different code to be used for gathering the results of a CALL in Perl, PHP, etc. (Need specific code here or elsewhere!)

Data not yet known - such as end_date, rating Optional data - such as middle_initial (though that might be better as the empty string) 0/0 - The result of certain computations, such as zero divided by zero. NULL is not equal to "" (blank string) or 0 (in case of integer). others? ...

Using the /p switch with the SET command you can define variables from an Input. This input can be a user Input (keyboard) : echo Enter your name : set /p name= echo Your name is %name% Which can be simplified like this : set /p name=Enter your name : echo Your name is %name% Or you can...

GSON does not support inheritance our of the box. Let's say we have the following class hierarchy: public class BaseClass { int a; public int getInt() { return a; } } public class DerivedClass1 extends BaseClass { int b; @Override public int getIn...

The Android Account Authenticator system can be used to make the client authenticate with a remote server. Three pieces of information are required: A service, triggered by the android.accounts.AccountAuthenticator. Its onBind method should return a subclass of AbstractAccountAuthenticator. An a...

libraryDependency is the SettingKey that handles 'managed' library dependencies, which are dependencies that are automatically downloaded, matching the supplied versions. To add a single dependency: libraryDependencies += "com.typesafe.slick" %% "slick" % "3.2.0-M1" ...

A repository is a place that SBT looks for libraryDependencies. If the build complains about not finding a dependency, it can be lacking the correct repository. Within SBT, the repositories are listed in the resolvers SettingKey: resolvers += "Flyway" at "https://flywaydb.org/repo&qu...

The standard structure for a project built by SBT is: projectName/ build.sbt project/ <SBT sub-build information> src/ main/ scala/ <Scala source files> java/ <Java source files> resources/ ...

If your project has this: scalaVersion := 2.11 // Replace '2.11' with the version of Scala your project is running on Then you can use %% to automatically get the version of the library compiled against the version of Scala the project is using: libraryDependencies += "com.typesafe.slick&...

A library can be 'pinned' to a specific version of Scala using the % operator between the groupId and the artifactId (the first two strings in a library dependency). In this example, we pin the library with the artifactId of slick to Scala version 2.10: libraryDependencies += "com.typesafe.sl...

On a desktop version of Chrome, the contents of the page can be inspected. This shows the document object model (DOM) of the HTML, the Cascading Style Sheet styles (CSS), and much more. Enter inspection by one of many options: Right click on a web page, and select Inspect From the Chrome Menu, ...

$ProductCollection=Mage::getModel('catalog/product')->getCollection(); Selecting the specific Attribute $ProductCollection->addAttributeToSelect(array('name', 'product_url', 'small_image')); Selecting the All Attribute $ProductCollection->addAttributeToSelect('*'); Add Filter on ...

What is a metaclass? In Python, everything is an object: integers, strings, lists, even functions and classes themselves are objects. And every object is an instance of a class. To check the class of an object x, one can call type(x), so: >>> type(5) <type 'int'> >>> typ...

Let's assume we have an entity status field with 3 options Tentative Pending Approved Our goal is to show different color for each status as follow: Tentative will be Red Pending will be Orange Approved will be Green The switch condition: =Switch(Fields!ItemStatus.Value = "Tentativ...

module main; auto getMemberNames(T)() @safe pure { string[] members; foreach (derived; __traits(derivedMembers, T)) { members ~= derived; } return members; } class Foo { int a; int b; } class Bar : Foo { int c; int d; int e...

Dependencies can be added for specific Build types: android { ... buildTypes { release { //... } debug { //.... } } } dependencies { debugCompile 'com.android.support:appcompat-v7:24.1.1' releaseCompile ...

Template Literals act like strings with special features. They are enclosed by by the back-tick `` and can be spanned across multiple lines. Template Literals can contain embedded expressions too. These expressions are indicated by a $ sign and curly braces {} //A single line Template Literal v...

Three main functions available (description from man pages): fromfile - A highly efficient way of reading binary data with a known data-type, as well as parsing simply formatted text files. Data written using the tofile method can be read using this function. genfromtxt - Load data from a t...