Tutorial by Examples: p

Using BASE_DIR to ensure app portability

It's a bad idea to hard code paths in your application. One should always use relative urls so that your code can work seamlessly across different machines. The best way to set this up is to define a variable like this import os BASE_DIR = os.path.dirname(os.path.dirname(__file__)) Then use th...

Django • Settings

Using Join in an Update

Joins can also be used in an UPDATE statement: CREATE TABLE Users ( UserId int NOT NULL, AccountId int NOT NULL, RealName nvarchar(200) NOT NULL ) CREATE TABLE Preferences ( UserId int NOT NULL, SomeSetting bit NOT NULL ) Update the SomeSetting column of the Prefere...

Microsoft SQL Server • Join

Transforming the elements of an Array with map(_:)

As Array conforms to SequenceType, we can use map(_:) to transform an array of A into an array of B using a closure of type (A) throws -> B. For example, we could use it to transform an array of Ints into an array of Strings like so: let numbers = [1, 2, 3, 4, 5] let words = numbers.map { Stri...

Swift Language • Arrays

Extracting values of a given type from an Array with flatMap(_:)

The things Array contains values of Any type. let things: [Any] = [1, "Hello", 2, true, false, "World", 3] We can extract values of a given type and create a new Array of that specific type. Let's say we want to extract all the Int(s) and put them into an Int Array in a safe ...

Swift Language • Arrays

Dynamic Parameters in Dapper

connection.Execute(@"some Query with @a,@b,@c", new {a=somevalueOfa,b=somevalueOfb,c=somevalueOfc});

Dapper.NET • Dynamic Parameters

Installation or Setup

python-requests is available on PyPI, the Python Package Index, which means it can be installed through pip: pip install requests Up-to-date source code can be found on the requests GitHub repository If you wish to install it from source, you can do this by either cloning the GitHub repository:...

python-requests • Getting started with python-requests

Basic Template

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-widt...

twitter-bootstrap • Getting started with twitter-bootstrap

Simple data structures

Structure data types are useful way to package related data and have them behave like a single variable. Declaring a simple struct that holds two int members: struct point { int x; int y; }; x and y are called the members (or fields) of point struct. Defining and using structs: ...

C Language • Structs

Trim empty spaces

Trim is used to remove write-space at the beginning or end of selection In MSSQL there is no single TRIM() SELECT LTRIM(' Hello ') --returns 'Hello ' SELECT RTRIM(' Hello ') --returns ' Hello' SELECT LTRIM(RTRIM(' Hello ')) --returns 'Hello' MySql and Oracle SELECT TRIM(' Hello ') ...

SQL • String Functions

Upper & lower case

SELECT UPPER('HelloWorld') --returns 'HELLOWORLD' SELECT LOWER('HelloWorld') --returns 'helloworld'

SQL • String Functions

Split

Splits a string expression using a character separator. Note that STRING_SPLIT() is a table-valued function. SELECT value FROM STRING_SPLIT('Lorem ipsum dolor sit amet.', ' '); Result: value ----- Lorem ipsum dolor sit amet.

SQL • String Functions

Installation and setup

Nginx is a Web server used to serve HTTP requests over the Internet. Nginx is available on Linux, Windows and other OSes as direct download, and can also be built from source. For detailed instructions see Nginx official reference. ubuntu/debian nginx stable version is available in official repo,...

nginx • Getting started with nginx

Installation or Setup

Detailed instructions on getting azureservicebus set up or installed.

azureservicebus • Getting started with azureservicebus

Creating a Specific Date

While the Java Date class has several constructors, you'll notice that most are deprecated. The only acceptable way of creating a Date instance directly is either by using the empty constructor or passing in a long (number of milliseconds since standard base time). Neither are handy unless you're lo...

Java Language • Date Class

Creating an Option value and pattern match

// The Option type can either contain Some value or None. fn find(value: i32, slice: &[i32]) -> Option<usize> { for (index, &element) in slice.iter().enumerate() { if element == value { // Return a value (wrapped in Some). return Some(index);...

Rust • Option

Minimal example

To write the traditional Hello World program in Rust, create a text file called hello.rs containing the following source code: fn main() { println!("Hello World!"); } This defines a new function called main, which takes no parameters and returns no data. This is where your progra...

Rust • Getting started with Rust

Applying a function to each element of an array

To apply a function to every item in an array, use array_map(). This will return a new array. $array = array(1,2,3,4,5); //each array item is iterated over and gets stored in the function parameter. $newArray = array_map(function($item) { return $item + 1; }, $array); $newArray now is a...

PHP • Executing Upon an Array

Tuples

A tuple is a fixed length ordered sequence of other Erlang terms. Each element in the tuple can be any type of term (any data type). 1> {1, 2, 3}. {1,2,3} 2> {one, two, three}. {one,two,three} 3> {mix, atom, 123, {<<1,2>>, [list]}}. {mix,atom,123,{<<1,2>>,[list...

Erlang Language • Data Types

Installation or Setup

XSLT is a special-purpose programming language; it is widely used for transforming XML documents either into a different XML format, into HTML, or into text-based formats. There are two main versions of XSLT in use: XSLT 1.0 and XSLT 2.0. XSLT 1.0 is more widely implemented but has many restriction...

xslt • Getting started with xslt

Hello World program

The following code creates a simple user interface containing a single Button that prints a String to the console on click. import javafx.application.Application; import javafx.scene.Scene; import javafx.scene.control.Alert; import javafx.scene.control.Alert.AlertType; import javafx.scene.contr...

javafx • Getting started with javafx