Tutorial by Examples: o

Select rows that match a condition

Generally, the syntax is: SELECT <column names> FROM <table name> WHERE <condition> For example: SELECT FirstName, Age FROM Users WHERE LastName = 'Smith' Conditions can be complex: SELECT FirstName, Age FROM Users WHERE LastName = 'Smith' AND (City = 'New York' OR C...

Microsoft SQL Server • Getting started with Microsoft SQL Server

Conditional logic and cross-platform handling

In a nutshell, conditional pre-processing logic is about making code-logic available or unavailable for compilation using macro definitions. Three prominent use-cases are: different app profiles (e.g. debug, release, testing, optimised) that can be candidates of the same app (e.g. with extra log...

C++ • Preprocessor

Macros

Macros are categorized into two main groups: object-like macros and function-like macros. Macros are treated as a token substitution early in the compilation process. This means that large (or repeating) sections of code can be abstracted into a preprocessor macro. // This is an object-like macro ...

C++ • Preprocessor

Aliases & Similar Functions

In PowerShell, there are many ways to achieve the same result. This can be illustrated nicely with the simple & familiar Hello World example: Using Write-Host: Write-Host "Hello World" Using Write-Output: Write-Output 'Hello world' It's worth noting that although Write-Outp...

PowerShell • Getting started with PowerShell

Execution of a JavaScript file in MongoDB

./mongo localhost:27017/mydb myjsfile.js Explanation: This operation executes the myjsfile.js script in a mongo shell that connects to the mydb database on the mongod instance accessible via the localhost interface on port 27017. localhost:27017 is not mandatory as this is the default port mongo...

MongoDB • Getting started with MongoDB

Uppercase and Lowercase Strings

To make all the characters in a String uppercase or lowercase: 2.2 let text = "AaBbCc" let uppercase = text.uppercaseString // "AABBCC" let lowercase = text.lowercaseString // "aabbcc" 3.0 let text = "AaBbCc" let uppercase = text.uppercased() // &qu...

Swift Language • Strings and Characters

Installation or Setup

Basic installation: You can download redux javascript file, using this link. Also you can install redux, using bower : bower install https://npmcdn.com/redux@latest/dist/redux.min.js Next, you need to include redux to your page: <html> <head> <script type="text/jav...

redux • Getting started with redux

Get product by sku

$sku = 'sku-goes-here'; $product = Mage::getModel('catalog/product')->loadByAttribute('sku', $sku);

magento • Get Products from Database

Get product by ID

$id = 1; $product = Mage::getModel('catalog/product')->load($id); if($product->getId()){ //product was found }

magento • Get Products from Database

Product collection - LIKE query

$collection = Mage::getModel('catalog/product')->getCollection(); $collection->addAttributeToFilter('sku', array('like' => 'UX%'));

magento • Get Products from Database

Get product collection by attribute

$collection = Mage::getModel('catalog/product')->getCollection(); // Using operator $collection->addAttributeToFilter('status', array('eq' => 1)); // Without operator (automatically uses 'equal' operator $collection->addAttributeToFilter('status', 1);

magento • Get Products from Database

Matching on an Option

If you are matching on an Option type: def f(x: Option[Int]) = x match { case Some(i) => doSomething(i) case None => doSomethingIfNone } This is functionally equivalent to using fold, or map/getOrElse: def g(x: Option[Int]) = x.fold(doSomethingIfNone)(doSomething) def h(x: ...

Scala Language • Pattern Matching

Enqueuing scripts in functions.php

If you want to add custom.js script that is located in the js/ folder of your theme, you'll need to enqueue it. In functions.php add <?php add_action( 'after_setup_theme', 'yourtheme_theme_setup' ); if ( ! function_exists( 'yourtheme_theme_setup' ) ) { function yourtheme_theme_setup()...

WordPress • Enqueuing scripts

Basic creation of factors

Factors are one way to represent categorical variables in R. A factor is stored internally as a vector of integers. The unique elements of the supplied character vector are known as the levels of the factor. By default, if the levels are not supplied by the user, then R will generate the set of uniq...

R Language • Factors

Select columns which are named after reserved keywords

When a column name matches a reserved keyword, standard SQL requires that you enclose it in double quotation marks: SELECT "ORDER", ID FROM ORDERS Note that it makes the column name case-sensitive. Some DBMSes have proprietary ways of quoting names. For example, SQL Serve...

SQL • SELECT

Grouping in ListView

asp:ListView introduced in ASP.NET WebForms framework 3.5 is the most flexible of all DataPresentation Controls in the framework. An example of Grouping using ListView (which will come handy as an image gallery) Objective: To display three images in a row using asp:ListView Markup <asp:ListVie...

ASP.NET • WebForms

Convenience functions to manipulate data.frames

Some convenience functions to manipulate data.frames are subset(), transform(), with() and within(). subset The subset() function allows you to subset a data.frame in a more convenient way (subset also works with other classes): subset(mtcars, subset = cyl == 6, select = c("mpg", "...

R Language • Data frames

DELETE certain rows with WHERE

This will delete all rows that match the WHERE criteria. DELETE FROM Employees WHERE FName = 'John'

SQL • DELETE

DELETE all rows

Omitting a WHERE clause will delete all rows from a table. DELETE FROM Employees See TRUNCATE documentation for details on how TRUNCATE performance can be better because it ignores triggers and indexes and logs to just delete the data.

SQL • DELETE

Function syntax

Functions can be written using several types of syntax function name() integer name name = 42 end function integer function name() name = 42 end function function name() result(res) integer res res = 42 end function Functions return values through a function result....

Fortran • Procedures - Functions and Subroutines