Join Kevin Skoglund for an in-depth discussion in this video Named scopes, part of Ruby on Rails 4 Essential Training.
…In this movie we will learn how to use named scopes in our models.…So far in this chapter we've learned to create, update, delete and find…records and we've done it without adding any additional code to our model.…We've been using the built in methods…provided by active record and active relation.…Rails gives us these features for free simply by defining…a model so that it inherits from active record base.…But now, we're going to write our own…custom queries, by defining named scopes in the model.…Name scopes allow us to define an active relation query, and store it in our model.…
We can call name scopes just like we call ActiveRelation query methods, and we can…even daisy chain them together with each…other, or with other active relation query methods.…And they can accept parameters just like a method would.…In Rails 4, named scopes require us to use Ruby's lambda syntax.…In Rails 3, that was optional, but in Rails 4, it's required.…I'll demonstrate how that works.…To define a scope inside your model, you use the keyword scope.…
- Why use Ruby on Rails?
- Installing Ruby on Rails on Mac and Windows
- Rendering templates and redirecting requests
- Generating and running database migrations
- Creating, updating, and deleting records
- Understanding association types
- Using layouts, partials, and view helpers
- Incorporating assets using asset pipeline
- Validating form data
- Authenticating users and managing user access
- Architecting RESTful applications
- Debugging and error handing
Skill Level Intermediate
1. What Is Ruby on Rails?
2. Installing Ruby on Rails on a Mac
3. Installing Ruby on Rails on a Windows Machine
4. Getting Started
5. Controllers, Views, and Dynamic Content
6. Databases and Migrations
7. Models, ActiveRecord, and ActiveRelation
9. Controllers and CRUD
10. Layouts, Partials, and View Helpers
13. Data Validation
14. User Authentication
15. Improving the Simple CMS
16. REST and RESTful Routes
17. Debugging and Error Handling
18. Introducing More Advanced Topics
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