**Creating models for handling business logic and database interactions** In this topic, we will delve into the world of CodeIgniter models, exploring how to create and utilize them to handle business logic and interact with your database. Models are a crucial part of the CodeIgniter framework, and mastering their creation and usage is essential for building robust and scalable applications. **What are Models in CodeIgniter?** In CodeIgniter, a model is a class that interacts with the database, encapsulates business logic, and provides a way to access and manipulate data. Models are designed to be reusable, modular, and independent of the controller and view layers. They act as an intermediary between the database and the application logic, making it easier to maintain and extend your codebase. **Benefits of Using Models** Using models in your CodeIgniter application offers several benefits, including: * **Separation of Concerns**: Models keep the database interactions separate from the business logic, making it easier to modify or replace either component without affecting the other. * **Reusability**: Models can be reused across multiple controllers and views, reducing code duplication and improving maintainability. * **Data Integrity**: Models help ensure data consistency by providing a single point of access to the database, reducing the risk of data corruption or inconsistencies. **Creating a Model in CodeIgniter** To create a model in CodeIgniter, follow these steps: 1. Create a new PHP file in the `app/Models` directory, naming it according to the model's purpose (e.g., `User.php`). 2. Extend the `CI_Model` class using the `extends` keyword. 3. Define the model's properties and methods, including database interactions and business logic. **Example Model: User Model** ```php // app/Models/User.php class User extends CI_Model { private $table = 'users'; public function __construct() { parent::__construct(); $this->load->database(); } public function get_user($id) { $this->db->where('id', $id); $query = $this->db->get($this->table); return $query->row(); } public function create_user($data) { $this->db->insert($this->table, $data); return $this->db->insert_id(); } public function update_user($id, $data) { $this->db->where('id', $id); $this->db->update($this->table, $data); return $this->db->affected_rows(); } public function delete_user($id) { $this->db->where('id', $id); $this->db->delete($this->table); return $this->db->affected_rows(); } } ``` **Key Concepts and Takeaways** * **Database Interactions**: Models provide a way to interact with the database, using CodeIgniter's database library. * **Business Logic**: Models encapsulate business logic, making it easier to modify or replace without affecting the database interactions. * **Separation of Concerns**: Models keep database interactions separate from business logic, improving maintainability and scalability. **Exercise** Create a new model in the `app/Models` directory, naming it according to the model's purpose (e.g., `Product.php`). Extend the `CI_Model` class and define the model's properties and methods, including database interactions and business logic. **Comment or Ask for Help** Have you created a model in CodeIgniter before? What were some challenges you faced, and how did you overcome them? Share your experiences and ask questions in the comments below. That's it for this topic! In the next section, we will explore managing relationships between database tables (one-to-one, one-to-many). Stay tuned!