how do I integrate calculated values into Laravel queries

1. Using `selectRaw` and `whereRaw` Methods

For simple calculations, you can use the `selectRaw` and `whereRaw` methods to include calculated values in your queries. These methods allow you to inject raw SQL expressions into your queries, which can be useful for complex calculations that involve multiple columns or functions[2].

2. Using `DB::raw` Method

You can also use the `DB::raw` method to include calculated values in your queries. This method allows you to specify a raw SQL expression that will be executed as part of the query. However, be aware that using `DB::raw` can introduce SQL injection vulnerabilities if not properly sanitized[2].

3. Using Eloquent's `addSelect` Method

For more complex calculations, you can use Eloquent's `addSelect` method to add a calculated value to the query's select clause. This method allows you to specify a custom select clause that includes the calculated value[2].

4. Using a Service Class

For complex business logic that involves multiple calculations, you can create a service class that encapsulates the logic. This approach helps to separate the logic from the controllers and models, making the code more maintainable and reusable[3].

5. Using Raw SQL

For very complex calculations that involve raw SQL, you can use Laravel's raw query methods such as `selectRaw`, `whereRaw`, `havingRaw`, and `orderByRaw`. These methods allow you to inject raw SQL expressions into your queries, but be aware that they can introduce SQL injection vulnerabilities if not properly sanitized[2].

Here is an example of using `selectRaw` to perform a complex calculation:

php
$orders = DB::table('orders')
    ->selectRaw('price * ? as price_with_tax', [1.0825])
    ->get();

In summary, the best approach depends on the complexity of the calculation and the requirements of your application. You can use `selectRaw`, `whereRaw`, `DB::raw`, `addSelect`, or raw SQL methods, each with its own advantages and considerations.