Tutorial by Examples: l

Detailed instructions on getting kdb set up or installed.

It is possible to DELETE data from a table if it matches (or mismatches) certain data in other tables. Let's assume we want to DELETEdata from Source once its loaded into Target. DELETE FROM Source WHERE EXISTS ( SELECT 1 -- specific value in SELECT doesn't matter FROM Target ...

6 class Item { constructor(text, type) { this.text = text; this.emphasis = false; this.type = type; } toHtml() { return `<${this.type}>${this.emphasis ? '<em>' : ''}${this.text}${this.emphasis ? '</em>' : ''}</${this.type}...

In this example we will extract all the web links from a website. I am using http://stackoverflow.com/ for illustration. Here recursion is used, where each obtained link's page is parsed for presence of an anchor tag and that link is again submitted to the same function. The condition if(add &&...

from multiprocessing import Pool def cube(x): return x ** 3 if __name__ == "__main__": pool = Pool(5) result = pool.map(cube, [0, 1, 2, 3]) Pool is a class which manages multiple Workers (processes) behind the scenes and lets you, the programmer, use. Pool(5) creat...

public class Foobar { public static void main(String[] args) { // example: Boolean ignore = null; if (ignore == false) { System.out.println("Do not ignore!"); } } } The pitfall here is that null is compared to false. Since w...

Here is an example of custom UITextField that takes only numerical text and discards all other. NOTE: For iPhone it is easy to do this using Number type keyboard, but for iPad there is no keyboard with Numbers only class NumberTextField: UITextField { required init(coder aDecoder: NSCoder) ...

If we want to disable all the actions like Copy, Paste, Replace, Select, etc from UITextField then we can use following custom text field: class CustomTextField: UITextField { var enableLongPressActions = false required init(coder aDecoder: NSCoder) { super.init(coder: aDecoder)! } o...

Function xyz returns two values a and b: def xyz(): return a, b Code calling xyz stores result into one variable assuming xyz returns only one value: t = xyz() Value of t is actually a tuple (a, b) so any action on t assuming it is not a tuple may fail deep in the code with a an unexpecte...

In this example we are going to create a view. A view is mostly used as a simple way of fetching data from multiple tables. Example 1: View with a select on one table. CREATE OR REPLACE VIEW LessonView AS SELECT L.* FROM Lesson L; Example 2: View with a select o...

Below we are going to create a table with 3 columns. The column Id must be filled is, so we define it NOT NULL. On the column Contract we also add a check so that the only value allowed is 'Y' or 'N'. If an insert in done and this column is not specified during the insert then default a 'N' is i...

iOS apps needs to be written in a way to provide security to data which is being transported over network. SSL is the common way to do it. Whenever app tries to call web services to pull or push data to servers, it should use SSL over HTTP, i.e. HTTPS. To do this, app must call https://server.com...

Parameter TypesReturn TypeInterface()voidRunnable()TSupplier()booleanBooleanSupplier()intIntSupplier()longLongSupplier()doubleDoubleSupplier(T)voidConsumer<T>(T)TUnaryOperator<T>(T)RFunction<T,R>(T)booleanPredicate<T>(T)intToIntFunction<T>(T)longToLongFunction<T>(...

You can define a function to be recursive with the rec keyword, so it can call itself. # let rec fact n = match n with | 0 -> 1 | n -> n * fact (n - 1);; val fact : int -> int = <fun> # fact 0;; - : int = 1 # fact 4;; - : int = 24 You can also define mutually re...

General Imports, using jinja2 to populate templates into htmls. import jinja2 import webapp2 Important import to use Users API: from google.appengine.api import users Setting of Jinja environment: [into the example the tehcnology selected to populate the information into the frontend] JINJ...

I used for this example webapp2 to cover the routing. from webapp2_extras.routes import RedirectRoute as Route Import from views: from views import MainPage MainPage is the handler set into root "/": urlpatterns = [ Route('/', MainPage), ]

Simple extract of index.html: <div class="sign-in"> {% if user %} [Passing the url we have the opportunity to logout the user] <a href="{{ url|safe }}">LOG OUT</a> [You can include here operations for user authenticated] ...

Once you're up with a new project with the basic template provided in the Introduction, you should be able to add a LUISRecognizer like so - var model = '' // Your LUIS Endpoint link comes here var recognizer = new builder.LuisRecognizer(model); Now, recognizer is a LUISRecognizer and can pa...

IMPORTANT!! Valet is a tool designed for macOS only. Prerequisites Valet utilizes your local machine's HTTP port (port 80), therefore, you will not be able to use if Apache or Nginx are installed and running on the same machine. macOS' unofficial package manager Homebrew is required to properly...

Suppose we have a POJO class User we need to validate. public class User { @NotEmpty @Size(min=5) @Email private String email; } and a controller method to validate the user instance public String registerUser(@Valid User user, BindingResult result); Let's extend the U...