Tutorial by Examples: er

using System; using System.Collections.Generic; using System.Linq; using System.Numerics; // also add reference to System.Numberics namespace ConsoleApplication33 { class Program { private static IEnumerable<BigInteger> Fibonacci() { BigInteger p...

This example shows how to update a UI component from a background thread by using a SynchronizationContext void Button_Click(object sender, EventArgs args) { SynchronizationContext context = SynchronizationContext.Current; Task.Run(() => { for(int i = 0; i < 10; i++) ...

To Illustrate the MERGE Statement, consider the following two tables - dbo.Product : This table contains information about the product that company is currently selling dbo.ProductNew: This table contains information about the product that the company will sell in the future. The foll...

Use EXCEPT to prevent updates to unchanged records MERGE TargetTable targ USING SourceTable AS src ON src.id = targ.id WHEN MATCHED AND EXISTS ( SELECT src.field EXCEPT SELECT targ.field ) THEN UPDATE SET field = src.field WHEN...

Feather is an implementation of Apache Arrow designed to store data frames in a language agnostic manner while maintaining metadata (e.g. date classes), increasing interoperability between Python and R. Reading a feather file will produce a tibble, not a standard data.frame. library(feather) pat...

// 2. Covariant result version of the base example, static type checking. class Top { public: virtual Top* clone() const = 0; virtual ~Top() = default; // Necessary for `delete` via Top*. }; class D : public Top { public: D* /* ← Covariant return */ clone() const over...

// 3. Covariant smart pointer result (automated cleanup). #include <memory> using std::unique_ptr; template< class Type > auto up( Type* p ) { return unique_ptr<Type>( p ); } class Top { private: virtual Top* virtual_clone() const = 0; public: unique_ptr&l...

Worse ViewController: // ... myMethod: function () { this.getView().lookup('myhappyfield').setValue(100); } //... View: //... items: [ { xtype: 'textfield', reference: 'myhappyfield' } ] //... Better ViewController: // ... myMethod: function () { ...

Overrides: Override file: Ext.define('MyApp.override.CornField', override: 'Ext.form.field.Text', initComponent: function () { this.callParent(arguments); this.setValue('Corn!'); } ); Use in app: { xtype: 'textfield' } Extensions: Override file: Ext...

Converts the specified string representation of a date and time to its DateTime equivalent using the specified format, culture-specific format information, and style. The format of the string representation must match the specified format exactly. The method returns a value that indicates whether th...

Resource with same path and name may exist in more than one JAR file on the classpath. Common cases are resources following a convention or that are part of a packaging specification. Examples for such resources are META-INF/MANIFEST.MF META-INF/beans.xml (CDI Spec) ServiceLoader properties con...

The received bytes have to be decoded with the correct character encoding to be interpreted as text: Python 3.x3.0 import urllib.request response = urllib.request.urlopen("http://stackoverflow.com/") data = response.read() encoding = response.info().get_content_charset() html = d...

From inside the interative Julia shell (also known as REPL), you can access the system's shell by typing ; right after the prompt: shell> From here on, you can type any shell comand and they will be run from inside the REPL: shell> ls Desktop Documents Pictures Templates Downloa...

textOnCurve(text,offset,x1,y1,x2,y2,x3,y3,x4,y4) Renders text on quadratic and cubic curves. text is the text to render offset distance from start of curve to text >= 0 x1,y1 - x3,y3 points of quadratic curve or x1,y1 - x4,y4 points of cubic curve or Example usage: textOnCurve("...

Coments "Comments are enclosed in double quotes. BEWARE: This is NOT a string!" "They can span multiple lines." Strings 'Strings are enclosed in sigle quotes.' 'Single quotes are escaped with a single quote, like this: ''.' '''' "<--This string contains one sin...

private final Logger logger = Logger.getLogger(getClass().getCanonicalName()); WebView webView = new WebView(); webEngine = webView.getEngine(); webEngine.setOnAlert(event -> logger.warning(() -> "JS alert: " + event.getData()));

Problem Cross-Site Request Forgery or CSRF can force an end user to unknowingly generate malicious requests to a web server. This attack vector can be exploited in both POST and GET requests. Let's say for example the url endpoint /delete.php?accnt=12 deletes account as passed from accnt parameter ...

You can concatenate strings separated by delimiter using the string_agg() function. If your individuals table is: NameAgeCountryAllie15USAAmanda14USAAlana20Russia You could write SELECT ... GROUP BY statement to get names from each country: SELECT string_agg(name, ', ') AS names, country FROM ...

The only major differences between this and a regular TCP connection are the private Key and the public certificate that you’ll have to set into an option object. How to Create a Key and Certificate The first step in this security process is the creation of a private Key. And what is this private ...

Let's create two simple tables: CREATE TABLE users (username text, email text); CREATE TABLE simple_users () INHERITS (users); Adding columns ALTER TABLE simple_users ADD COLUMN password text; simple_users ColumnTypeusernametextemailtextpasswordtext Adding the same column to the parent ta...