Tutorial by Examples: ti

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...

kotlin-gradle-plugin is used to compile Kotlin code with Gradle. Basically, its version should correspond to the Kotlin version you want to use. E.g. if you want to use Kotlin 1.0.3, then you need to aplly kotlin-gradle-plugin version 1.0.3 too. It's a good idea to externalize this version in gradl...

Protocol Oriented Programming is a useful tool in order to easily write better unit tests for our code. Let's say we want to test a UIViewController that relies on a ViewModel class. The needed steps on the production code are: Define a protocol that exposes the public interface of the class Vi...

import ( "io/ioutil" "path/filepath" "gopkg.in/yaml.v2" ) func main() { filename, _ := filepath.Abs("config/config.yml") yamlFile, err := ioutil.ReadFile(filename) var config Config err = yaml.Unmarshal(yamlFile, &c...

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...

Extension methods are useful for adding functionality to enumerations. One common use is to implement a conversion method. public enum YesNo { Yes, No, } public static class EnumExtentions { public static bool ToBool(this YesNo yn) { return yn == YesNo.Yes; ...

By default, the navigation pattern works like a stack of pages, calling the newest pages over the previous pages. You will need to use the NavigationPage object for this. Pushing new pages ... public class App : Application { public App() { MainPage = new NavigationPage(new ...

Modal pages can created in three ways: From NavigationPage object for full screen pages For Alerts and Notifications For ActionSheets that are pop-ups menus Full screen modals ... // to open await Navigation.PushModalAsync(new ModalPage()); // to close await Navigation.PopModalAsync(); ...

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, ...

SELECT Name FROM Customers WHERE PhoneNumber IS NULL Selection with nulls take a different syntax. Don't use =, use IS NULL or IS NOT NULL instead.

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 ...

The interface you defined needs to be implemented in every targeted platform. For iOS this is done through the AVFoundation framework. The following implementation of the ITextToSpeech interface handles speaking a given text in English. using AVFoundation; public class TextToSpeechiOS : ITextToS...

The Android specific implementation is a bit more complex because it forces you to inherit from a native Java.Lang.Object and forces you to implement the IOnInitListener interface. Android requires you to provide a valid Android context for a lot of the SDK methods it exposes. Xamarin.Forms exposes ...

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...

Given this data User_IDCompletion_Date12016-07-2012016-07-2122016-07-2022016-07-2122016-07-22 ;with CTE as (SELECT *, ROW_NUMBER() OVER (PARTITION BY User_ID ORDER BY Completion_Date DESC) Row_Num FROM Data) SELECT * FORM CTE WHERE Row_Num <= n Us...

Note that this deals with the creation of a collection of type Map, which is distinct from the map method. Map Creation Map[String, Int]() val m1: Map[String, Int] = Map() val m2: String Map Int = Map() A map can be considered a collection of tuples for most operations, where the first e...

Sitecore ships with a set of standard indexes pre-configured which you can extend, or you can define your own. Of the pre-configured, sitecore_master_index & sitecore_web_index are of most interest for your site search. These are the predefined indexes for all of your Sitecore items in the tree ...

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...

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 ...