Tutorial by Examples: p

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...

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...

Anonymous types provide a convenient way to encapsulate a set of read-only properties into a single object without having to explicitly define a type first. The type name is generated by the compiler and is not available at the source code level. The type of each property is inferred by the compiler...

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] ...

If we want our app data to be protected against iTunes backups, we have to skip our app data from being backed up in iTunes. Whenever iOS device backed up using iTunes on macOS, all the data stored by all the apps is copied in that backup and stored on backing computer. But we can exclude our app ...

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...

Tooltip is a directive, it allows the user to show hint text while the user mouse hover over an element. A tooltip would have the following markup. <span tooltip-direction="left" tooltip="On the Left!">Left</span> <button tooltip="some message" ...

Assume that, we implement a simple API and we have the following models. class Parent(models.Model): name = models.CharField(max_length=50) class Child(models.Model): parent = models.ForeignKey(Parent) child_name = models.CharField(max_length=80) And we want to return a respo...

Datepicker allow the user to select date and time. <md2-datepicker [(ngModel)]="date"></md2-datepicker> see for more details here

Md2Collapse : Collapse is a directive, it's allow the user to toggle visiblity of the section. Examples A collapse would have the following markup. <div [collapse]="isCollapsed"> Lorum Ipsum Content </div> Md2Accordion : Accordion it's allow the user to toggle vis...

Detailed instructions on getting avr set up or installed.

creating custom exception 'P2222': create or replace function s164() returns void as $$ begin raise exception using message = 'S 164', detail = 'D 164', hint = 'H 164', errcode = 'P2222'; end; $$ language plpgsql ; creating custom exception not assigning errm: create or replace function s...

copy (select oid,relname from pg_class limit 5) to stdout;

In Kotlin, we can declare variable which can hold null reference. Suppose we have a nullable reference a, we can say "if a is not null, use it, otherwise use some non-null value x" var a: String? = "Nullable String Value" Now, a can be null. So when we need to access value o...

Detailed instructions on getting greasemonkey set up or installed.

Function using promises: function myAsyncFunction() { return aFunctionThatReturnsAPromise() // doSomething is a sync function .then(result => doSomething(result)) .catch(handleError); } So here is when Async/Await enter in action in order to get clean...

Angular 2 wrapper library for Dropzone. npm install angular2-dropzone-wrapper --save-dev Load the module for your app-module import { DropzoneModule } from 'angular2-dropzone-wrapper'; import { DropzoneConfigInterface } from 'angular2-dropzone-wrapper'; const DROPZONE_CONFIG: DropzoneCon...

Prerequisites: Java is installed Selenium is extracted in a folder (Contains 2 files, and 1 folder) Follow these steps to set up IntelliJ Idea for Selenium. Click On "New Project". Choose Java < "Hello World" Application Type the name of the Project, and create it....