Tutorial by Examples: ai

Foreign Keys constraints ensure data integrity, by enforcing that values in one table must match values in another table. An example of where a foreign key is required is: In a university, a course must belong to a department. Code for the this scenario is: CREATE TABLE Department ( Dept_Code...

rails new my_app cd my_app Gemfile gem 'friendly_id', '~> 5.1.0' # Note: You MUST use 5.0.0 or greater for Rails 4.0+ rails generate friendly_id rails generate scaffold user name:string slug:string:uniq rake db:migrate edit app/models/user.rb class User < ApplicationRecord exten...

Excel has many Formulas built right in. Here are a few examples of some of the basic Formulas that might be handy to know when getting started with Excel: Important Note : The name and Syntax of these Formulas vary on the language of your Excel installation! For example this Function here : in Eng...

You can set flash data in controller just using this syntax $this->session->set_flashdata('message', 'Message you want to set'); Here 'message' is identifier for access data in view. You can Set more than one message by just changing identifier. for ex $this->session->set_flashdata...

You can simply access the fashdata in view like this <?php echo $this->session->flashdata('message'); ?> For access multiple message just change identifier For Ex. <?php echo $this->session->flashdata('my_alert'); ?> <?php echo $this->session->flashdata('my_wa...

If you have multiple asynchronous tasks that needs to occur one after the other, you will need to chain together their promise objects. Here is a simple example: function First() { console.log("Calling Function First"); return $.get("/ajax/GetFunction/First"); } fu...

/// <summary> /// Post Method with Input/ data to post in JSON format /// </summary> /// <returns> Json formated data </returns> public string GetJsonData3() { IOperations _Obj = ClsOperations.GetOperations(); string url = "htt...

In Spark (scala) we can get our data into a DataFrame in several different ways, each for different use cases. Create DataFrame From CSV The easiest way to load data into a DataFrame is to load it from CSV file. An example of this (taken from the official documentation) is: import org.apache.spar...

It's possible to specify several type constraints for generics using the where clause: func doSomething<T where T: Comparable, T: Hashable>(first: T, second: T) { // Access hashable function guard first.hashValue == second.hashValue else { return } // Access compa...

The andThen function allows update call composition. Can be used with the pipeline operator (|>) to chain updates. Example: You are making a document editor, and you want that each modification message you send to your document, you also save it: import Update.Extra exposing (andThen) import U...

To illustrate this, here is a function that has 3 different "wrong" behaviors the parameter is completely stupid: we use a user-defined expression the parameter has a typo: we use Oracle standard NO_DATA_FOUND error another, but not handled case Feel free to adapt it to your standa...

Swift: centralManager.scanForPeripherals(withServices: nil, options: nil) Objective C: [centralManager scanForPeripheralsWithServices:nil options:nil];

Swift: let services = [CBUUID(string: SERVICE1_UUID), CBUUID(string: SERVICE2_UUID)] centralManager.scanForPeripherals(withServices: services, options: nil) Objective C: NSArray *services = @[[CBUUID UUIDWithString:SERVICE1_UUID], [CBUUID UUIDWithString:SERVICE2_UUID]]; [centralManager scanFo...

success and Error : A success callback that gets invoked upon successful completion of an Ajax request. A failure callback that gets invoked in case there is any error while making the request. Example: $.ajax({ url: 'URL', type: 'POST', data: yourData, datat...

it caused by your batch size too small, which lead to a lot of ROS Containers created and reach the limitation(1024 default). you should do defragment using TupleMover task(mergeout) before the error raised. To do troubleshooting: ROS Containers viewed from the projections. select * from STOR...

If you have a lot of commands, you shouldn't put them all in the main class. Make a new class and have it implement CommandExecutor Add the following to the class: @Override public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) { } In your...

You can write detailed signals with the [Signal (detailed = true)] attribute. public class Emitter : Object { [Signal (detailed = true)] public signal void detailed_signal (); public void emit_with_detail (string detail) { this.detailed_signal[detail] (); } } void...

Add the hyperloop gem to your rails (4.0 - 5.1) Gemfile bundle install Add the hyperloop manifest to the application.js file: // app/assets/javascripts/application.js ... //= hyperloop-loader Create your react components, and place them in the hyperloop/components directory # app/hyperl...

One common scenario is to wait for a number of requests to finish before continuing. This can be accomplished using the forkJoin method. In the following example, forkJoin is used to call two methods that return Observables. The callback specified in the .subscribe method will be called when both O...

# install sbt with homebrew (if you didn't) brew install sbt # - create a new scala project # - name your project name when asked like: hello-world sbt new sbt/scala-seed.g8 # go to the new project directory that you named cd hello-world # run sbt to open the sbt shell sbt # run you...