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I want to, when given a particular model, return all the related models it is associated with. For example:
class Dog < ActiveRecord::Base has_many :bones belongs_to :master end d = Dog.first d.associations #<== should return [Bone, Master] Is there a way to do this already without having to roll my own? Failing that, any suggestions for the best way to do this?
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EDUQAS. WJEC. All Exam Boards. Entity relationship modelling is a top-down technique that is used to visualise and help understand the entities and the relationships between them. A data model — presented in the form of an entity relationship diagram — is one of the first steps of database design.
One to one relationship For example, every user is associated with a single post or maybe multiple posts, but in this relationship, we will retrieve the single post of a user. To define a relationship, we need first to define the post() method in User model.
In a relational database, a one-to-many relationship exists when one row in table A may be linked with many rows in table B, but one row in table B is linked to only one row in table A. It is important to note that a one-to-many relationship is not a property of the data, but rather of the relationship itself.
with() function is used to eager load in Laravel. Unless of using 2 or more separate queries to fetch data from the database , we can use it with() method after the first command. It provides a better user experience as we do not have to wait for a longer period of time in fetching data from the database.
Dog.reflect_on_all_associations http://api.rubyonrails.org/classes/ActiveRecord/Reflection/ClassMethods.html#M001405
You wouldn't do this on an instance but on the model itself.
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