Join Kevin Skoglund for an in-depth discussion in this video Query methods: order, limit, and offset, part of Ruby on Rails 4 Essential Training.
…Limit, is going to limit the results that are returned.…
It becomes especially important when a lot of records match our conditions.…Let's imagine that we have a database with 20,000 customers.…We wouldn't want to see all 20,000 customers on our screen at the same time.…We'd probably want to view them as pages.…Maybe 20 at a time.…In that case, we would limit the results to 20.…If we want to view page 51 of those results.…We still only want to get 20 records back.…But we also need to skip over the first…1000 records that are on the previous 50 pages.…To do that we would use offset.…Offset let's us skip over records before selecting the results to return.…
These three query methods can all be changed together.…And they can also work together, with our conditions that we saw in the last movie.…The combination of these three methods, with our query conditions…will help us to find the right records in the database.…And I think the argument for a limit, and offset are pretty self-explanatory.…We're just passing in an integer there, telling it how…
- 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 Beginner
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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