Book Image

Yii2 By Example

By : Fabrizio Caldarelli
Book Image

Yii2 By Example

By: Fabrizio Caldarelli

Overview of this book

Yii is a high-performance PHP framework best for developing Web 2.0 applications. It provides fast, secure, and professional features to create robust projects, however, this rapid development requires the ability to organize common tasks together to build a complete application. It's all too easy to get confused; this is where this book comes in. This book contains a series of practical project examples for developers starting from scratch. Each section contains the most relevant theories for every topic as you walk through developing each project, focusing on key aspects that commonly confuse users. The book starts with all the framework’s basic concepts, such as controllers and views, to introduce you to Yii and creating your first application, a simple news reader. You will be learn to configure URL rules to make a pretty URL, essential for search engine optimization. Next, you will walk through Model and ActiveRecord, key concepts in database interaction. The second application you will develop is a reservation system that allows you to manage rooms, customers, and reservations. For this, you will use database connection through SQL and ActiveRecord. More complex than the first one, this application will introduce you to the advanced template of Yii 2, splitting the app into two parts: a frontend for all visitors and a backend for the admin. Finally, you will move on to the last two applications: one that allows connections from remote clients, through RESTful components of Yii 2, and another that creates and organizes automatic tasks using the console application structure of Yii 2.
Table of Contents (20 chapters)
Yii2 By Example
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Working with relationships


ActiveRecord provides us with skills to work with relationships between database tables. Yii2 employs two methods to establish the relationship between the current and other ActiveRecord classes: hasOne and hasMany, which return an ActiveQuery based on the multiplicity of the relationship.

The first method hasOne() returns at most one related record that matches the criteria set by this relationship, and hasMany() returns multiple related records that match the criteria set by this relationship.

Both methods require that the first parameter is the class name of the related ActiveRecord and that the second parameter is the pair of primary keys that are involved in the relationship: the first key is relative to a foreign ActiveRecord and the second key is related to the current ActiveRecord.

Usually, hasOne() and hasMany() are accessed from properties that identify which object (or objects) will be returned.

The method in this example is:

class Room extends ActiveRecord...