Privileges
The CREATE VIEW statement requires the CREATE VIEW privilege for the view, and some privilege for each column selected by the SELECT statement. For columns used elsewhere in the SELECT statement, you must have the SELECT privilege. If the OR REPLACE clause is present, you must also have ...
Statement-level parallel hints are the easiest:
SELECT /*+ PARALLEL(8) */ first_name, last_name FROM employee emp;
Object-level parallel hints give more control but are more prone to errors; developers often forget to use the alias instead of the object name, or they forget to include some objec...
4.0.3
Using a CustomTabsIntent, it is now possible to configure Chrome custom tabs in order to customize key UI components in the browser that is opened from your app.
This is a good alternative to using a WebView for some cases. It allows loading of a web page with an Intent, with the added abil...
In C#, there are two different kinds of equality: reference equality and value equality. Value equality is the commonly understood meaning of equality: it means that two objects contain the same values. For example, two integers with the value of 2 have value equality. Reference equality means that ...
There are few approaches available there:
You can subscribe for keyboard appearance events notifications and change offset manually:
//Swift 2.0+
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourVCClas...
Controller class names are pluralized. The reason is the controller controls multiple instances of object instance.
For Example: OrdersController would be the controller for an orders table. Rails will then look for the class definition in a file called orders_controller.rb in the /app/controllers ...
Private inheritance is useful when it is required to restrict the public interface of the class:
class A {
public:
int move();
int turn();
};
class B : private A {
public:
using A::turn;
};
B b;
b.move(); // compile error
b.turn(); // OK
This approach efficiently pr...
Predefined macros are those that the compiler defines (in contrast to those user defines in the source file). Those macros must not be re-defined or undefined by user.
The following macros are predefined by the C++ standard:
__LINE__ contains the line number of the line this macro is used on, an...
To show some content in a new window, a Stage needs to be created. After creation and initialisation show or showAndWait needs to be called on the Stage object:
// create sample content
Rectangle rect = new Rectangle(100, 100, 200, 300);
Pane root = new Pane(rect);
root.setPrefSize(500, 500);
...
app/assets/javascripts/channels/notifications.coffee
App.notifications = App.cable.subscriptions.create "NotificationsChannel",
connected: ->
# Called when the subscription is ready for use on the server
$(document).on "change", "input", (e)=>
...
Java-like enumerations can be created by extending Enumeration.
object WeekDays extends Enumeration {
val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value
}
def isWeekend(day: WeekDays.Value): Boolean = day match {
case WeekDays.Sat | WeekDays.Sun => true
case _ => false
}
isWeekend...
An alternative to extending Enumeration is using sealed case objects:
sealed trait WeekDay
object WeekDay {
case object Mon extends WeekDay
case object Tue extends WeekDay
case object Wed extends WeekDay
case object Thu extends WeekDay
case object Fri extends WeekDay
case objec...
Creating a Snackbar can be done as follows:
Snackbar.make(view, "Text to display", Snackbar.LENGTH_LONG).show();
The view is used to find a suitable parent to use to display the Snackbar. Typically this would be a CoordinatorLayout that you've defined in your XML, which enables adding ...
The String List passed as a parameter to the share() method contains the paths of all the files you want to share.
It basically loops through the paths, adds them to Uri, and starts the Activity which can accept Files of this type.
public static void share(AppCompatActivity context,List<Strin...
To avoid verbose null checking, the ?. operator has been introduced in the language.
The old verbose syntax:
If myObject IsNot Nothing AndAlso myObject.Value >= 10 Then
Can be now replaced by the concise:
If myObject?.Value >= 10 Then
The ? operator is particularly powerful when you...
The NameOf operator resolves namespaces, types, variables and member names at compile time and replaces them with the string equivalent.
One of the use cases:
Sub MySub(variable As String)
If variable Is Nothing Then Throw New ArgumentNullException("variable")
End Sub
The old sy...
This new feature makes the string concatenation more readable. This syntax will be compiled to its equivalent String.Format call.
Without string interpolation:
String.Format("Hello, {0}", name)
With string interpolation:
$"Hello, {name}"
The two lines are equivalent and ...
