Tutorial by Examples: w

SELECT name, caption as title, year, pages FROM books UNION SELECT name, title, year, 0 as pages FROM movies When combining 2 record sets with different columns then emulate the missing ones with default values.

Note: There will be some Objective-c in this example.. We will make a wrapper to C++ in this example, So don't worry to much about it. First start Xcode and create a project. And select a Cocoa application Delete all sources except the Info.plist file.(Your app won't work without it) Creat...

#include <Windows.h> DWORD WINAPI DoStuff(LPVOID lpParameter) { // The new thread will start here return 0; } int main() { // Create a new thread which will start at the DoStuff function HANDLE hThread = CreateThread( NULL, // Thread attributes ...

Firstly, one can use quiver, where one doesn't have to deal with unhandy normalized figure units by use of annotation drawArrow = @(x,y) quiver( x(1),y(1),x(2)-x(1),y(2)-y(1),0 ) x1 = [10 30]; y1 = [10 30]; drawArrow(x1,y1); hold on x2 = [25 15]; y2 = [15 25]; drawArrow(x2,y2) ...

The most important object in the Browser Object Model is the window object. It helps in accessing information about the browser and its components. To access these features, it has various methods and properties. MethodDescriptionwindow.alert()Creates dialog box with message and an OK buttonwindow....

When INSERTing, you can use OUTPUT INSERTED.ColumnName to get values from the newly inserted row, for example the newly generated Id - useful if you have an IDENTITY column or any sort of default or calculated value. When programatically calling this (e.g., from ADO.net) you would treat it as a nor...

At the command prompt: $ echo "Hello World" Output: Hello World To create a script, create a text document with the following content: #!/bin/sh echo "Hello World" Save the script with the name hello.sh (or any filename) and make the script executable by giving the f...

There is a constructor of the same name: DT <- data.table( x = letters[1:5], y = 1:5, z = (1:5) > 3 ) # x y z # 1: a 1 FALSE # 2: b 2 FALSE # 3: c 3 FALSE # 4: d 4 TRUE # 5: e 5 TRUE Unlike data.frame, data.table will not coerce strings to factors by default: sa...

We can read from a text file: dt <- fread("my_file.csv") Unlike read.csv, fread will read strings as strings, not as factors by default. See the [topic on fread][need_a_link] for more examples.

For efficiency, data.table offers a way of altering a data.frame or list to make a data.table in-place: # example data.frame DF = data.frame(x = letters[1:5], y = 1:5, z = (1:5) > 3) # modification setDT(DF) Note that we do not <- assign the result, since the object DF has been modifi...

# example data DT1 = data.table(x = letters[1:2], y = 1:2, z = (1:2) > 3) Due to the way data.tables are manipulated, DT2 <- DT1 will not make a copy. That is, later modifications to the columns or other attributes of DT2 will affect DT1 as well. When you want a real copy, use DT2 = copy(...

The DISTINCT clause after SELECT eliminates duplicate rows from the result set. CREATE TABLE `car` ( `car_id` INT UNSIGNED NOT NULL PRIMARY KEY, `name` VARCHAR(20), `price` DECIMAL(8,2) ); INSERT INTO CAR (`car_id`, `name`, `price`) VALUES (1, 'Audi A1', '20000'); INSERT INTO CA...

It is sometimes argued that, for the sake of efficiency, we must accept the use of non-monotonic constructs in real-world Prolog programs. There is no evidence for this. Recent research indicates that the pure monotonic subset of Prolog may not only be sufficient to express most real-world programs...

To interact with WebElements in a webpage, first we need to identify the location of the element. By is the keyword available in selenium. You can locate the elements By.. By ID By Class Name By TagName By Name By Link Text By Partial Link Text By CSS Selector By XPath Using JavaScript ...

set can also be invoked with just one argument. When called with just one argument, it returns the contents of that argument. % set x 235 235 % set x 235

<svg height="80" width="160"> <ellipse cx="80" cy="40" rx="50" ry="30" style="fill:yellow; stroke:black; stroke-width:2" /> </svg> Rendered:

The chan-signal crate provides a solution to handle OS signal using channels, altough this crate is experimental and should be used carefully. Example taken from BurntSushi/chan-signal. #[macro_use] extern crate chan; extern crate chan_signal; use chan_signal::Signal; fn main() { // S...

The nix crate provides an UNIX Rust API to handle signals, however it requires using unsafe rust so you should be careful. use nix::sys::signal; extern fn handle_sigint(_:i32) { // Be careful here... } fn main() { let sig_action = signal::SigAction::new(handle_sigint, ...

A very basic docker-compose.yml looks like this: version: '2' services: hello_world: image: ubuntu command: [/bin/echo, 'Hello world'] This file is making it so that there's a hello_world service, that's initialized from the ubuntu:latest image and that, when it's run, it just runs...

Ionic 1.2 officially supports deployment as a website If you're not using any Cordova plugins then there is no problem (if you really wish to) to upload the contents of the www folder to your server, and woila - you'll have the same app. However, it is important to note that Ionic 1 never intended...