Beginning Rails 4 (Expert's Voice in Web Development)
Adam Gamble, Rida Al Barazi
Format: PDF / Kindle (mobi) / ePub
Beginning Rails 4 is a book that will guide you from never having programmed with Ruby, to having a Rails application built and deployed to the web. You'll learn how to combine all the components of Rails to develop your own web applications.
gently guides you through designing your application, writing tests for the application, and then writing the code to make your application work as expected.
delete multiple rows by primary key, you must pass an actual array object. The following works, because it’s a single array (containing three items) and thus a single argument: Model.delete([1,2,3]). Deleting with Conditions You can delete all rows that match a given condition with the delete_all class method. The following deletes all articles before a certain date: >> Article.delete_all("published_at < '2011-01-01'") >> 0 The return value of delete_all is the number of records deleted.
To get started, create a fresh Article object: >> article = Article.new => #
article_id: 8, name: "Guest", ...>] >> user.replies.size => 1 Advanced Finding Chapter 5covered use of the find class method in Active Record. This section expands on different find operations using the where method. Building advanced finder methods is one of the most important things you do with your models. Using the where Method The most basic condition style is the hash syntax. Active Record takes the Hash passed to the where method and turns the keys into column names and the values into
application controller. Likewise, ApplicationController inherits all the capabilities of its parent, ActionController::Base. The ActionController::Base class effectively endows your articles controller with its special abilities. The application controller is the base from which all the controllers you make inherit. Because it’s the parent of all controllers in your application, it’s a great place to put methods that you want accessible in every controller. By looking at the articles controller,
the most popular of which are GET and POST. Both are methods for requesting a web page; the difference is in how the request is sent. GET is the simpler of the two. 140 Chapter 7 ■ Action Pack: Working with the View and the Controller It includes all the information about the request as part of the URL. POST sends information invisibly, which is to say, as part of the request header and not part of the URL. So, you can’t type a POST request into your browser’s location bar. Every time you