Tutorial by Examples: u

Suppose we want to have the following behaviour - We have a heading (say h3 element) and on clicking it, we want it to become an input box so that we can modify heading name. React makes this highly simple and intuitive using component states and if else statements. (Code explanation below) // I ha...

When you are getting started with ElasticSearch (ES) it might be good to have a graphical tool that helps you explore your data. A plugin called elasticsearch-head does just that. To install it, do the following: Find out in which folder ES is installed: ls -l $(which elasticsearch) cd into this...

ElasticSearch has a well-documented JSON API, but you'll probably want to use some libraries that handle that for you: Elasticsearch - the official low level wrapper for the HTTP API Elasticsearch-rails - the official high level Rails integration that helps you to connect your Rails models...

FOR XML PATH and STUFF to concatenate the multiple rows into a single row: select distinct t1.id, STUFF( (SELECT ', ' + convert(varchar(10), t2.date, 120) FROM yourtable t2 where t1.id = t2.id FOR XML PATH ('')) , 1,...

Ubuntu binaries are available for both 32-bit and 64-bit architectures source /etc/lsb-release && echo "deb http://download.rethinkdb.com/apt $DISTRIB_CODENAME main" | sudo tee /etc/apt/sources.list.d/rethinkdb.list wget -qO- https://download.rethinkdb.com/apt/pubkey.gpg | sudo a...

User defined table functions represented by org.apache.hadoop.hive.ql.udf.generic.GenericUDTF interface. This function allows to output multiple rows and multiple columns for a single input. We have to overwrite below methods : 1.we specify input and output parameters abstract StructObjectInspe...

Sample XML <Students> <Student> <Name> <First>Ashley</First> <Last>Smith</Last> </Name> <Grades> <Exam1>A</Exam1> <Exam2>B</Exam2> ...

Update build.sbt with : scalaVersion := "2.11.8" // Make sure to have installed Scala 11 sparkVersion := "2.0.0" // Make sure to have installed Spark 2.0 Note that when compiling with sbt package, the .jar will now be created in target/scala-2.11/, and the .jar name will al...

ML Transformers now generates org.apache.spark.ml.linalg.VectorUDT instead of org.apache.spark.mllib.linalg.VectorUDT. They are also mapped locally to subclasses of org.apache.spark.ml.linalg.Vector. These are not compatible with old MLLib API which is moving towards deprecation in Spark 2.0.0. //...

The Firebase auth system is the source of a users uid, displayName, photoURL, and maybe email. Password based accounts set these persistent values in the auth system via the .updateProfile method. Storing these values in the Realtime Database, rDB, users node poses the issue of stale data. Displa...

package com.example; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class Application { //main entry point public static void main(String[] args) { SpringApplication.run...

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> ...

This custom UserControl will appear as a regular combobox, but unlike the built-in ComboBox object, it can show the user a default string of text if they have not made a selection yet. In order to accomplish this, our UserControl will be made up of two Controls. Obviously we need an actual ComboBox...

QML came with rich set of visual elements. Using only QML we can build complex applications with these elements. Also it's very easy to build your own element based on set of standard items like Rectangle, Button, Image etc. Moreover, we can use items like Canvas to build element with custom paint...

Goto - http://www.jorambarrez.be/blog/2010/08/02/tutorial-a-bpmn-2-0-hello-world-with-activiti-5-0-alpha4-in-5-steps/ A very Good and detailed tutorial by Joram Barrez (one of the core Developer of Activiti)

Plugins are a way for a developer to modify a chart as it is being created. Chart.js calls all plugins at the following chart states: Start of initialization End of initialization Start of update After the chart scales have calculated Start of datasets update End of datasets update End of u...

// 1. Connect to the database (this example with MySQL) $host = 'localhost'; $database = 'users'; $user = 'root'; $password = ''; $dsn = "mysql:host=$host;dbname=$database"; $pdo = new PDO($dsn, $user, $password); // 2. Prepare your query // 2.1 First way $query_1 = "SELE...

Denormalization and a flat database structure is neccessary to efficiently download separate calls. With the following structure, it is also possible to maintain two-way relationships. The disadvantage of this approach is, that you always need to update the data in multiple places. For an example, ...

You can use the COUNT() function to return the number of records that match a query. The following 'Employee' table contains employee ID numbers and their associated manager's ID number. Employee_IDManager_ID123722373763424545635745594563 A COUNT() statement can be used to find out how many employ...

[TestCase(0, 0, 0)] [TestCase(34, 25, 59)] [TestCase(-1250, 10000, 8750)] public void AddNumbersTest(int a, int b, int expected) { // Act int result = a + b; // Assert Assert.That(result, Is.EqualTo(expected)); }