Tutorial by Examples: d

Opening a database is an asynchronous operation. We need to send a request to open our database and then listen for events so we know when it's ready. We'll open a DemoDB database. If it doesn't exist yet, it will get created when we send the request. The 2 below says that we're asking for version...

In HBase, data are stored in tables with columns. Columns are regrouped in column families, which can be for example "personal" or "professional", each of these containing specific informations. To create a table, you need to use the Admin Object, create it using : Admin admin ...

In HBase, you can use 4 types of operations Get : retrieves a row Put : inserts one or more row(s) Delete : delete a row Scan : retrieves several rows If you simply want to retrieve a row, given its row_key you can use the Get object: Get get = new Get(Bytes.toBytes("my_row_key")...

There are two ways to define an anonymous function: the full syntax and a shorthand. Full Anonymous Function Syntax (fn [x y] (+ x y)) This expression evaluates to a function. Any syntax you can use with a function defined with defn (&, argument destructuring, etc.), you can also do with wi...

(defn print-some-items [[a b :as xs]] (println a) (println b) (println xs)) (print-some-items [2 3]) This example prints the output 2 3 [2 3] The argument is destructured and the items 2 and 3 are assigned to the symbols a and b. The original argument, the entire vector [2 ...

In the node JS command prompt, inside your loopback project, type the following command to create a new model. slc loopback:model If you have installed LoopBack CLI tool, you can create model with: lb model The command prompt will request informations about the model to create. In this examp...

console.dir(object) displays an interactive list of the properties of the specified JavaScript object. The output is presented as a hierarchical listing with disclosure triangles that let you see the contents of child objects. var myObject = { "foo":{ "bar":"d...

VBA supports 2 calendars : Gregorian and Hijri The Calendar property is used to modify or display the current calendar. The 2 values for the Calendar are: ValueConstantDescription0vbCalGregGregorian calendar (default)1vbCalHijriHijri calendar Example Sub CalendarExample() 'Cache the curren...

CDate() CDate() converts something from any datatype to a Date datatype Sub CDateExamples() Dim sample As Date ' Converts a String representing a date and time to a Date sample = CDate("September 11, 2001 12:34") Debug.Print Format$(sample, "yyyy-mm-dd hh:nn:...

How To Install ANTLR in Eclipse (Last tested on Indigo and ANTLR IDE 2.1.2) Install Eclipse. Download ANTLR complete binaries jar that includes ANTLR v2. Extract to a temp directory. Copy the antlr-n.n folder to an appropriate permanent location, for example the same folder that Eclipse is in...

Server Syntax var io = require('socket.io')(80); io.on('connection', function (mysocket) { //custom event called `private message` mysocket.on('private message', function (from, msg) { console.log('I received a private message by ', from, ' saying ', msg); }); //internal `di...

Suppose we want to read and stack a bunch of similarly-formatted files. The quick solution is: rbindlist(lapply(list.files(patt="csv$"), fread), id=TRUE) We might not be satisfied with this for a couple reasons: It might run into errors when reading with fread or when stacking with ...

The available commands will be displayed, including a brief description, in tabular format. In Windows 10 the following commands are listed: CommandDescriptionASSOCDisplays or modifies file extension associations.ATTRIBDisplays or changes file attributes.BREAKSets or clears extended CTRL+C checkin...

Install node modules npm install express npm install socket.io Node.js server const express = require('express'); const app = express(); const server = app.listen(3000,console.log("Socket.io Hello Wolrd server started!")); const io = require('socket.io')(server); io.on('connec...

Open Graph is a standard for metadata that extends the normal information contained within a site's head markup. This enables websites such as Facebook to display deeper and richer information about a website in a structured format. This information is then automatically displayed when users share l...

Split vector of texts using one pattern: stri_split_fixed(c("To be or not to be.", "This is very short sentence.")," ") # [[1]] # [1] "To" "be" "or" "not" "to" "be." # # [[2]] # [1] "This" ...

This is an simple example to create a mysql server with docker 1.- create docker-compose.yml: Note: If you want to use same container for all your projects, you should create a PATH in your HOME_PATH. If you want to create it for every project you could create a docker directory in your project. ...

/// <summary> /// Read configuration values from app.config and convert to specified types /// </summary> public static class ConfigurationReader { /// <summary> /// Get value from AppSettings by key, convert to Type of default value or typ...

[TestFixture] public class UnitTest1 { class Message { public string Text { get; } = "Hello World"; } [Test] public void HelloWorldTest() { // Act var message = new Message(); // Assert Assert.That(message.Tex...

root: build.gradle buildscript { repositories { jcenter() } dependencies { classpath 'com.android.tools.build:gradle-experimental:0.8.0-alpha4' } } allprojects { repositories { jcenter() } } app: build.gradle apply plugin: 'com.andro...