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GROUP BY is used in combination with aggregation functions. Consider the following table: orderIduserIdstoreNameorderValueorderDate143Store A2520-03-2016257Store B5022-03-2016343Store A3025-03-2016482Store C1026-03-2016521Store A4529-03-2016 The query below uses GROUP BY to perform aggregated calc...

When something fails in your transaction code and you want to undo it, you can rollback your transaction: BEGIN TRY BEGIN TRANSACTION INSERT INTO Users(ID, Name, Age) VALUES(1, 'Bob', 24) DELETE FROM Users WHERE Name = 'Todd' COMMIT TRANSACTION END TRY...

Creating a hub A quick configuration for a hub and node setup in selenium grid. For more information see: Grid 2 docs Requirements To set up a grid hub you need the flowing: Selenium-server-standalone-.jar Creating the hub To Create a Hub you need to run the selenium server. Download Se...

In CSS3, we can stack multiple background in the same element. #mydiv { background-image: url(img_1.png), /* top image */ url(img_2.png), /* middle image */ url(img_3.png); /* bottom image */ background-position: right bottom, ...

The below code will turn the table with an id of tableid into a DataTable, as well as return a DataTables API instance: $(document).ready(function() { $('#tableid').DataTable(); }); Compare this to the below code, which will turn the table into a DataTable but will not return a DataTables ...

Yes, you need to SETKEY pre 1.9.6 In the past (pre 1.9.6), your data.table was sped up by setting columns as keys to the table, particularly for large tables. [See intro vignette page 5 of September 2015 version, where speed of search was 544 times better.] You may find older code making use of t...

A non-blocking assignment (<=) is used for assignment inside edge-sensitive always blocks. Within a block, the new values are not visible until the entire block has been processed. For example: module flip( input clk, input reset ) reg f1; reg f2; always @ (posedge clk) begin ...

Demo HTML <script type="x-template" id="form-template"> <label>{{inputLabel}} :</label> <input type="text" v-model="name" /> </script> <div id="app"> <h2>{{appName}}</h2> <form-co...

The Scala compiler prefixes every argument in the parameter list by default with val. This means that, by default, case classes are immutable. Each parameter is given an accessor method, but there are no mutator methods. For example: case class Foo(i: Int) val fooInstance = Foo(1) val j = fooIn...

We start off with $db, an instance of the PDO class. After executing a query we often want to determine the number of rows that have been affected by it. The rowCount() method of the PDOStatement will work nicely: $query = $db->query("DELETE FROM table WHERE name = 'John'"); $count = ...

A true relational database must go beyond throwing data into a few tables and writing some SQL statements to pull that data out. At best a badly designed table structure will slow the execution of queries and could make it impossible for the database to function as intended. A database table shoul...

Apply will be used when when table valued function in the right expression. create a Department table to hold information about departments. Then create an Employee table which hold information about the employees. Please note, each employee belongs to a department, hence the Employee table has ref...

In normal mode, we can increment the nearest number on the line at or after the cursor with <C-a> and decrement it with <C-x>. In the following examples, the cursor position is indicated by ^. Incrementing and decrementing numbers for i in range(11): ^ <C-x> decrements ...

The core idea behind the Feature Branch Workflow is that all feature development should take place in a dedicated branch instead of the master branch. This encapsulation makes it easy for multiple developers to work on a particular feature without disturbing the main codebase. It also means the mast...

The Math.random() function should give random numbers that have a standard deviation approaching 0. When picking from a deck of card, or simulating a dice roll this is what we want. But in most situations this is unrealistic. In the real world the randomness tends to gather around an common normal...

Flash dispatches Events for most of its objects. One of the most basic event is ENTER_FRAME, which is dispatched (at the framerate of the SWF) on every display list object. import flash.display.Sprite; import flash.events.Event; var s:Sprite = new Sprite(); s.addEventListener(Event.ENTER_FRAME...

Most functions in F# are created with the let syntax: let timesTwo x = x * 2 This defines a function named timesTwo that takes a single parameter x. If you run an interactive F# session (fsharpi on OS X and Linux, fsi.exe on Windows) and paste that function in (and add the ;; that tells fsharpi ...

Template JS code Template.templateName.onCreated(function(){ this.subscribe('subsription1'); this.subscribe('subscription2'); }); Template HTML code <template name="templateName"> {{#if Template.subscriptionsReady }} //your actual view with data. it can ...

Defining our terms By array here we mean a Lua table used as a sequence. For example: -- Create a table to store the types of pets we like. local pets = {"dogs", "cats", "birds"} We're using this table as a sequence: a group of items keyed by integers. Many langua...

This example wraps the asynchronous method oauth2.client.getToken(callback) from the package NPM package simple-oauth2into a Fiber so that the method may be called synchronously. const oauth2 = require('simple-oauth2')(credentials); const credentials = { clientID: '#####', clientSecret...