Tutorial by Examples: s

This command will drop index in the table. It works on SAP ASE server. Syntax: DROP INDEX [table name].[index name] Example: DROP INDEX Cars.index_1

Look at the contents of /etc/redhat-release cat /etc/redhat-release Here is the output from a Fedora 24 machine: Fedora release 24 (Twenty Four) As mentioned in the debian-based response, you can also use the lsb_release -a command, which outputs this from a Fedora 24 machine: LSB Version: ...

ReactJS is an open-source, component based front end library responsible only for the view layer of the application. It is maintained by Facebook. ReactJS uses virtual DOM based mechanism to fill in data (views) in HTML DOM. The virtual DOM works fast owning to the fact that it only changes individ...

Post::find()->all(); // SELECT * FROM post or the shorthand (Returns an active record model instance by a primary key or an array of column values.) Post::findAll(condition); returns an array of ActiveRecord instances. Find All with where Condition $model = User::find() ->w...

OPERATORS $postsGreaterThan = Post::find()->where(['>', 'created_at', '2016-01-25'])->all(); // SELECT * FROM post WHERE created_at > '2016-01-25' $postsLessThan = Post::find()->where(['<', 'created_at', '2016-01-25'])->all(); // SELECT * FROM post WHERE created_at < '2...

<?php namespace models; use yii\db\ActiveRecord; use yii\behaviors\TimestampBehavior; class Post extends ActiveRecord { public static function tableName() { return 'post'; } public function rules() { ...

Generators can be used to implement coroutines: # create and advance generator to the first yield def coroutine(func): def start(*args,**kwargs): cr = func(*args,**kwargs) next(cr) return cr return start # example coroutine @coroutine def adder(sum = 0): ...

Twig is a templating language that compiles to optimized PHP code. It is primarily used for outputting HTML, but can also be used to output any other text-based format. It is a standalone component that can be easily integrated into any PHP project. It provides many excellent features: Autoescap...

To get your most recent stash after running git stash, use git stash apply To see a list of your stashes, use git stash list You will get a list that looks something like this stash@{0}: WIP on master: 67a4e01 Merge tests into develop stash@{1}: WIP on master: 70f0d95 Add user role to lo...

async functions do not replace the Promise type; they add language keywords that make promises easier to call. They are interchangeable: async function doAsyncThing() { ... } function doPromiseThing(input) { return new Promise((r, x) => ...); } // Call with promise syntax doAsyncThing() ...

When accessing arrays with pointers, there are no bounds check and therefore no IndexOutOfRangeException will be thrown. This makes the code faster. Assigning values to an array with a pointer: class Program { static void Main(string[] args) { unsafe { int...

CSS3 introduces a few new units, including the rem unit, which stands for "root em". Let's look at how rem works. First, let's look at the differences between em and rem. em: Relative to the font size of the parent. This causes the compounding issue rem: Relative to the font size of t...

You can use the !$ to reduce repetition when using the command line: $ echo ping ping $ echo !$ ping You can also build upon the repetition $ echo !$ pong ping pong $ echo !$, a great game pong, a great game Notice that in the last example we did not get ping pong, a great game because...

Prerequisites iOS 8 or later, macOS 10.9 or later, all versions of tvOS and watchOS. Xcode 8.0 or later required. Realm Swift 2.3.0 was the last version to support Swift 2.x and Xcode 7.3. Installation Dynamic Framework Download the latest release of Realm and extract the zip....

The second value in the curly braces dictates the length of the replacement string. By adjusting the second value to be positive or negative, the alignment of the string can be changed. string.Format("LEFT: string: ->{0,-5}<- int: ->{1,-5}<-", "abc", 123); string....

// Integral types as hex string.Format("Hexadecimal: byte2: {0:x2}; byte4: {0:X4}; char: {1:x2}", 123, (int)'A'); // Integers with thousand separators string.Format("Integer, thousand sep.: {0:#,#}; fixed length: >{0,10:#,#}<", 1234567); // Integer with leading zero...

Use existing .NET classes instantly with PowerShell by using [class]::Method(args): PS C:\> [guid]::NewGuid() Guid ---- 8874a185-64be-43ed-a64c-d2fe4b6e31bc Similarly, in PowerShell 5+ you may use the New-Guid cmdlet: PS C:\> New-Guid Guid ---- 8874a185-64be-43ed-a64c-d2fe4b6e31...

If value types are assigned to variables of type object they are boxed - the value is stored in an instance of a System.Object. This can lead to unintended consequences when comparing values with ==, e.g.: object left = (int)1; // int in an object box object right = (int)1; // int in an object bo...

Boxed value types can only be unboxed into their original Type, even if a conversion of the two Types is valid, e.g.: object boxedInt = (int)1; // int boxed in an object long unboxedInt1 = (long)boxedInt; // invalid cast This can be avoided by first unboxing into the original Type, e.g.: lon...

The fetch function does not send cookies by default. There are two possible ways to send cookies: Only send cookies if the URL is on the same origin as the calling script. fetch('/login', { credentials: 'same-origin' }) Always send cookies, even for cross-origin calls. fetch('htt...