Tutorial by Examples: b

var MongoClient = require('mongodb').MongoClient; //connection with mongoDB MongoClient.connect("mongodb://localhost:27017/MyDb", function (err, db) { //check the connection if(err){ console.log("connection failed."); }else{ ...

The NamedParameterJdbcTemplate class adds support for programming JDBC statements using named parameters, as opposed to programming JDBC statements using only classic placeholder ( '?') arguments. The NamedParameterJdbcTemplate class wraps a JdbcTemplate, and delegates to the wrapped JdbcTempl...

Any @Component or @Configuration could be marked with @Profile annotation @Configuration @Profile("production") public class ProductionConfiguration { // ... } The same in XML config <beans profile="dev"> <bean id="dataSource" class="&l...

class ConversationsTableViewController: UITableViewController, NSFetchedResultsControllerDelegate { private var fetchedResultsController: NSFetchedResultsController<Conversation>! override func viewDidLoad() { super.viewDidLoad() initializeFetchedResultsController() } private...

The most common use of formatting is to control display of numeric information contained in the cells in a consistent format, such as currency, a certain number of digits to the right of the decimal point, etc. There are several categories for numbers, such as Currency, Accounting, Percentage, and ...

This example shows how to create a cube using 2D transformation methods skewX() and skewY() on pseudo elements. HTML: <div class="cube"></div> CSS: .cube { background: #dc2e2e; width: 100px; height: 100px; position: relative; margin: 50px; } .cube::be...

To list the available databases, use the following command: $ show databases name: databases name ---- _internal devices ... list of your databases You can connect to one specific database: $ use <database_name> By using a single database, the scope for each subsequent query wi...

It is possible to DELETE data from a table if it matches (or mismatches) certain data in other tables. Let's assume we want to DELETEdata from Source once its loaded into Target. DELETE FROM Source WHERE EXISTS ( SELECT 1 -- specific value in SELECT doesn't matter FROM Target ...

In this example we will extract all the web links from a website. I am using http://stackoverflow.com/ for illustration. Here recursion is used, where each obtained link's page is parsed for presence of an anchor tag and that link is again submitted to the same function. The condition if(add &&...

SCSS syntax resembles more like a CSS syntax but SASS syntax is little bit different from SCSS but both produces exactly the same CSS code. In SASS we are not ending the style properties with semicolon(;) but in SCSS we are ending the style properties with (;). In SCSS we used paranthesis {} to ...

Option Explicit Sub CheckWorksheetsDiagram() Debug.Print Worksheets(1).Name Debug.Print Charts(1).Name Debug.Print Sheets(1).Name End Sub The result: Sheet1 Chart1 Chart1

public class Foobar { public static void main(String[] args) { // example: Boolean ignore = null; if (ignore == false) { System.out.println("Do not ignore!"); } } } The pitfall here is that null is compared to false. Since w...

%TYPE: Used to declare a field with the same type as that of a specified table's column. DECLARE vEmployeeName Employee.Name%TYPE; BEGIN SELECT Name INTO vEmployeeName FROM Employee WHERE RowNum = 1; DBMS_OUTPUT.PUT_LINE(vEmp...

Below we are going to create a table with 3 columns. The column Id must be filled is, so we define it NOT NULL. On the column Contract we also add a check so that the only value allowed is 'Y' or 'N'. If an insert in done and this column is not specified during the insert then default a 'N' is i...

Parameter TypesReturn TypeInterface()voidRunnable()TSupplier()booleanBooleanSupplier()intIntSupplier()longLongSupplier()doubleDoubleSupplier(T)voidConsumer<T>(T)TUnaryOperator<T>(T)RFunction<T,R>(T)booleanPredicate<T>(T)intToIntFunction<T>(T)longToLongFunction<T>(...

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 ...

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...

DirectByteBuffer is special implementation of ByteBuffer that has no byte[] laying underneath. We can allocate such ByteBuffer by calling: ByteBuffer directBuffer = ByteBuffer.allocateDirect(16); This operation will allocate 16 bytes of memory. The contents of direct buffers may reside outside ...

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...

We use the get method to go to a website. For Example, this would open google public static void main(String[] args) throws InterruptedException { System.setProperty("webdriver.chrome.driver", "path of the exe file\\chromedriver.exe"); WebDriver driver = new ChromeDriv...