Tutorial by Examples: r

SELECT department, COUNT(*) AS "Man_Power" FROM employees GROUP BY department HAVING COUNT(*) >= 10; Using GROUP BY ... HAVING to filter aggregate records is analogous to using SELECT ... WHERE to filter individual records. You could also say HAVING Man_Power >= 10 since HAVIN...

Fabric is a modular mobile platform that provides useful kits you can mix to build your application. Crashlytics is a crash and issue reporting tool provided by Fabric that allows you to track and monitor your applications in detail. How to Configure Fabric-Crashlytics Step 1: Change your build....

For enabling Proguard configurations for your application you need to enable it in your module-level gradle file. You need to set the value of minifyEnabled to true. buildTypes { release { minifyEnabled true proguardFiles getDefaultProguardFile('proguard-android.t...

Example of calling an extension method as an extension and as a regular method. public Class MyClass Sub Main() 'Extension called directly on the object. Dim Version = Assembly.GetExecutingAssembly.GetVersionFromAssembly() 'Called as a regular method. ...

main.component.ts import {Component} from "@angular/core"; @Component({ selector: "main", template: ` <StackLayout> <TextField hint="some text"></TextField> <Button text="Click me" class="btn">...

Create a Dictionary<TKey, TValue> from an IEnumerable<T>: using System; using System.Collections.Generic; using System.Linq; public class Fruits { public int Id { get; set; } public string Name { get; set; } } var fruits = new[] { new Fruits { Id = 8 , Nam...

There are times when an include file has to generate different output from the preprocessor depending on whether the compiler is a C compiler or a C++ compiler due to language differences. For example a function or other external is defined in a C source file but is used in a C++ source file. Since...

A common problem in code that uses multidimensional arrays, arrays of pointers, etc. is the fact that Type** and Type[M][N] are fundamentally different types: #include <stdio.h> void print_strings(char **strings, size_t n) { size_t i; for (i = 0; i < n; i++) puts(str...

When allocating multidimensional arrays with malloc, calloc, and realloc, a common pattern is to allocate the inner arrays with multiple calls (even if the call only appears once, it may be in a loop): /* Could also be `int **` with malloc used to allocate outer array. */ int *array[4]; int i; ...

So far, we have looked at inserting a node at the beginning of a singly linked list. However, most of the times you will want to be able to insert nodes elsewhere as well. The code written below shows how it is possible to write an insert() function to insert nodes anywhere in the linked lists. #...

There's no built in way to search a list for a particular item. However Programming in Lua shows how you might build a set that can help: function Set (list) local set = {} for _, l in ipairs(list) do set[l] = true end return set end Then you can put your list in the Set and test for m...

Objective-C UIColor *color = [UIColor redColor]; NSString *textToFind = @"redword"; NSMutableAttributedString *attrsString = [[NSMutableAttributedString alloc] initWithAttributedString:yourLabel.attributedText]; // search for word occurrence NSRange range = [yourLabel.text rangeO...

To be able to debug an application is very important to understand the flow of an application's logic and data. It helps solving logical bugs and adds value to the programming experience and code quality. Two popular gems for debugging are debugger (for ruby 1.9.2 and 1.9.3) and byebug (for ruby &g...

com.google.gson library needs to be added to use this code. Here is the example string: String companyDetails = {"companyName":"abcd","address":"abcdefg"} JSON strings can be parsed using below syntax in Java: JsonParser parser = new JsonParser(); Json...

The word count program is like the "Hello World" program in MapReduce. Hadoop MapReduce is a software framework for easily writing applications which process vast amounts of data (multi-terabyte data-sets) in-parallel on large clusters (thousands of nodes) of commodity hardware in a relia...

PM2 lets you run your nodejs scripts forever. In the event that your application crashes, PM2 will also restart it for you. Install PM2 globally to manager your nodejs instances npm install pm2 -g Navigate to the directory in which your nodejs script resides and run the following command each t...

To start the process: $ forever start index.js warn: --minUptime not set. Defaulting to: 1000ms warn: --spinSleepTime not set. Your script will exit if it does not stay up for at least 1000ms info: Forever processing file: index.js List running Forever instances: $ forever list i...

In Python 2, True, False and None are built-in constants. Which means it's possible to reassign them. Python 2.x2.0 True, False = False, True True # False False # True You can't do this with None since Python 2.4. Python 2.x2.4 None = None # SyntaxError: cannot assign to None In ...

If you need to sort the results of a UNION, use this pattern: ( SELECT ... ) UNION ( SELECT ... ) ORDER BY Without the parentheses, the final ORDER BY would belong to the last SELECT.

Strict mode also prevents you from deleting undeletable properties. "use strict"; delete Object.prototype; // throws a TypeError The above statement would simply be ignored if you don't use strict mode, however now you know why it does not execute as expected. It also prevents you fr...