**Course Title:** Mastering Laravel Framework: Building Scalable Modern Web Applications **Section Title:** Working with Databases and Eloquent ORM **Topic:** Query Builder vs. Eloquent ORM: When to use which. **Introduction** In the previous topics, we explored Laravel's Eloquent ORM and database migrations. However, Laravel provides another powerful tool for database interactions: the Query Builder. In this topic, we'll delve into the Query Builder, comparing it to Eloquent ORM and discussing when to use each. **What is the Query Builder?** The Query Builder is a database query builder provided by Laravel, which allows you to build and execute database queries using a fluent, expressive syntax. It provides a more direct way to interact with your database, bypassing the Eloquent ORM's abstraction. **Query Builder vs. Eloquent ORM: Key Differences** 1. **Abstraction Level**: Eloquent ORM provides a higher level of abstraction, allowing you to interact with your database tables as objects. The Query Builder, on the other hand, provides a lower level of abstraction, requiring you to write database queries manually. 2. **Performance**: The Query Builder can be marginally faster than Eloquent ORM since it eliminates the overhead of Eloquent's abstraction layer. 3. **Complexity**: The Query Builder is more suitable for complex database queries, which can be challenging to express using Eloquent ORM. 4. **Relationships**: Eloquent ORM provides built-in support for relationships between tables, while the Query Builder requires manual handling of relationships. **When to use the Query Builder** 1. **Complex Database Queries**: Use the Query Builder for complex database queries that require fine-grained control over the query structure. 2. **Performance-Critical Operations**: Use the Query Builder in performance-critical operations where every millisecond counts. 3. **Raw Database Queries**: Use the Query Builder when you need to execute raw database queries, such as creating or modifying database schema. **Example: Using the Query Builder for a Complex Database Query** ```php use Illuminate\Support\Facades\DB; $users = DB::table('users') ->where('age', '>', 18) ->where('country', 'USA') ->whereIn('city', ['New York', 'Los Angeles']) ->get(); ``` **When to use Eloquent ORM** 1. **Simple Database Operations**: Use Eloquent ORM for simple database operations, such as CRUD (Create, Read, Update, Delete) operations. 2. **Relationship Management**: Use Eloquent ORM when working with relationships between tables. 3. **Object-Oriented Database Interactions**: Use Eloquent ORM when you want to interact with your database tables as objects. **Example: Using Eloquent ORM for a Simple Database Operation** ```php use App\Models\User; $users = User::where('age', '>', 18)->get(); ``` **Conclusion** In conclusion, the Query Builder and Eloquent ORM are both powerful tools for database interactions in Laravel. While the Query Builder provides a lower level of abstraction and is suitable for complex database queries, Eloquent ORM provides a higher level of abstraction and is suitable for simple database operations and relationship management. As a general rule of thumb, use the Query Builder when you need fine-grained control over your database queries, and use Eloquent ORM for simple database operations and when working with relationships between tables. **Resources** * Laravel Documentation: [Query Builder](https://laravel.com/docs/9.x/queries) * Laravel Documentation: [Eloquent ORM](https://laravel.com/docs/9.x/eloquent) **What's Next?** In the next topic, we'll explore Laravel's built-in authentication system. **Leave a Comment/Ask for Help** If you have any questions or need further clarification on the topic, please leave a comment below.