**Course Title:** Mastering CodeIgniter Framework: Fast, Lightweight Web Development **Section Title:** Database Integration with CodeIgniter **Topic:** Introduction to CodeIgniter’s Query Builder for CRUD operations **Overview:** In this topic, we will delve into the world of database integration with CodeIgniter, focusing on the Query Builder, a powerful tool that simplifies database interactions. We will explore the basics of the Query Builder, learn how to create, read, update, and delete (CRUD) operations, and understand the benefits of using this approach. By the end of this topic, you will be able to effectively use CodeIgniter’s Query Builder to interact with your database. **What is the Query Builder?** The Query Builder is a part of CodeIgniter that provides a simple and efficient way to interact with your database. It allows you to build queries using a fluent interface, making it easy to read and write database queries. **Advantages of using the Query Builder:** * Simplifies database interactions * Reduces errors and improves readability * Provides a powerful and flexible way to interact with your database **Creating a Query using the Query Builder:** To create a query using the Query Builder, you need to create a new instance of the `Query` class and specify the table name and the desired operation. ```php $query = $this->db->query("SELECT * FROM users WHERE name = 'John Doe'"); ``` **Common Query Builder Methods:** * `from()`: Specify the table name * `where()`: Specify the condition for the query * `or_where()`: Specify an alternative condition for the query * `group_by()`: Specify the columns to group by * `having()`: Specify the condition for the GROUP BY clause * `limit()`: Specify the limit for the query * `order_by()`: Specify the column to order by * `get()`: Execute the query and return the result **Example Query:** ```php $query = $this->db->query("SELECT * FROM users ->from('users') ->where('name', 'John Doe') ->where('email', 'john.doe@example.com') ->order_by('id', 'desc') ->get()"); // If you want to display the result, you can do so like this: $result = $query->result_array(); foreach ($result as $row) { echo $row['name']. "<br>"; } ``` **Best Practices:** * Use the Query Builder for all database interactions * Avoid using raw SQL queries whenever possible * Use parameterized queries to prevent SQL injection attacks * Keep your queries simple and focused on the task at hand **Practical Takeaways:** * Use the Query Builder to create and read data from your database * Understand the common Query Builder methods and how to use them effectively * Practice using the Query Builder to build more complex queries **Conclusion:** In this topic, we have covered the basics of the Query Builder in CodeIgniter, including how to create and read data from your database. We have also discussed the benefits of using the Query Builder and provided best practices for using it effectively. By applying the concepts and techniques learned in this topic, you will be able to simplify your database interactions and improve the performance of your CodeIgniter applications. **Leaving a comment or asking for help?** Share your thoughts, ask questions, or seek clarification on any of the topics covered in this topic.